Thoughts so far:
If you're bothered about other people looking and commenting then this could be the car for you. I've only had the car for a week but the amount of people turning their heads is already higher than in my old car over nearly three years of ownership (I had none in the C, in case you wondered

). Partly this can probably be attributed to the colour, but general consensus seems to be that this the SB is a winning design.
I loved my previous car (S204 250 CDI) and never did I think for a minute the step up to the CLS SB would be quite so marked, experience wise. To my eye it's a beautiful car inside and out and the facelift has evolved an already great product further. It looks like nothing else on the market and has real road presence.
Starting off with the headlights, which are impressive. My old car had ILS, but this one is taking it a step further with 24 individual LEDs shaping the throw of light so as not to dazzle oncoming cars. Admittedly I've only tried it briefly but have yet to have cars flash me. In my old car I got flashed all the time.
I love the 19" wheels too - I had initially had my mind set on a S205 and these are the alloys I were going to pick. The fact that they came as standard on the SB was a bonus. The tyres are massive, 285/30 at the back, 255/35 up front, giving the car a great stance.
As for the colour - I nearly went for Iridium Silver, but my missus really didn't like it. In hindsight she was right. Not just for the fact that the white metallic suits the car - I just don't think I would have felt the same way about the car as it was the same colour as my old one. Funny thing, colours - I never used to be that fussed.
It actually worked out better in the end, not going for the silver, as this one came with a few nice extras fitted in addition to Premium Plus (360 degree camera, privacy glass, Designo paint), all of which I really think enhance the overall appearance and enjoyment of the car.
It drives nice. It drives in a straight line too, which is a bonus. My old car always pulled slightly to the left, which I understand is somewhat a trademark of the C. It actually feels sportier than my old car, something I definitely did not expect. It feels more planted round the bends, and I guess this can be attributed to the rear multi-link air suspension. Probably full air suspension would have been nice, but it wasn't at the top of my shopping list.
Speaking of shopping list. I did contemplate the 350d engine, but couldn't justify the extra outlay. My old car was a 250 CDI, which I chose over the 220 CDI and in hindsight I'm not sure the extra money was worth it, just for the extra grunt. I'd say the 220d is adequate, although admittedly it needs working harder than it's big brother. It's very smooth and quiet, which was a nice surprise, coming from of the S204.
The frameless doors are a very nice touch and suit the overall character of the car. The privacy glass is REALLY dark - passengers in the rear seat certainly won't be spotted and it also goes really well against the white I reckon. Useful for the kids in summer, too.
Interior is standard full leather but black, so not much to add on that point really. The quality of the leather used is acceptable, although obviously won't be a patch on the dearer hides available. The seat side bolsters are more supportive than those found in the S204 (AMG Sport).
I like the fact that they refrained from fitting the touchpad on top of the rotary wheel. I had a S205 on loan for a day and could not get on with it. Maybe if I were left handed it'd make more sense, but I found myself resorting to using the rotary wheel instead. It also makes for a cleaner overall look I reckon.
Strangely, I like the hand-operated gearshift stalk too. To me, this car is a real leftie choice and it seems fitting somehow that it shouldn't be without its quirkinesses. Foot operated parking brake adds further to the fact.
Dials and buttons are not dissimilar to the old C-class, and more or less identical to the E-class. Seat warmers are standard. Nice. I've seen some reviews commenting on there being too many buttons. Not so, I especially appreciate the keypad as it is tactile and useful when making calls and navigating through IVR systems ("press 1 for this, 2 for that") on the move.
The new Mercedes Telematics are impressive. I managed to tether to my smart phone (Android) as well as connecting to my home broadband. TuneIn and Mercedes Radio apps come bundled along with a few other apps; I can now listen to Swedish radio on the move, which I find astonishing. Google Maps also come pre-installed (not sure yet if you can actually download more apps, need to do more research), although I'm not sure when I'll use it as the built-in sat nav is more integrated with COMAND hence easier and more responsive to use.
I uploaded a few pictures of the 360 degree camera so I won't go on about it too much, other than again I have to mention the bird-eye view. The vehicle in the left-hand half of the screen is obviously super-imposed, but the cameras are still very impressive and must have a really wide angle as they catch so much of the cars surroundings. There are also several other views - back/front wheels can be viewed, which is useful for getting right near the curb without damaging those precious rims.
The (main) reason I went for the Premium Plus package was to get the Harman/Kardon sound system. It's immense. It initially sounded a bit lacklustre, but I wasn't put off as I had heard similar stories in the past - the speakers just need a bit of a run-in period. It plays DVDs too and the other night the kids were watching the Gruffalo in Logic 7 mode - they were mesmerised. I've been humming and arring about fitting a home cinema system but I think I'll just watch films in the car from now on instead
DAB is standard. So far I have found reception acceptable (although I have yet to make a trip further afield so time will tell!) and navigating through stations is a doddle. I can now listen to Planet Rock and BBC Radio 6!
Other toys include electric glass sunroof, memory package (fully electric seats) and keyless go. All useful extras - I'm just about getting used to not having to get my key out all the time. The glass sunroof lets a certain degree of welcome natural light in. Memory seats are good - the boy likes to sit up front and I usually raise the seat so he can see better. I've now stored his setting in memory as well as a more normal seat position, so can easily flick between the two.
Are there any negatives? It's a big car. Big and wide. The cameras go some way of mitigating it, but parking in public spaces takes a bit of concentration and as always my preference is to go for an end space, wherever possible. That said, I used to do the same in my old car so I think I have a touch of OCD when it comes to parking.