1st one has the more reliable engine.
Less economical both as auto and because the later 651 engine is more economical.
In the OM639 Vito / Viano (made 2004 - 2014) the 646 (2148cc) engine was fitted till sometime 2010. The 651 (2143cc) engine was then fitted and even fitted in the 447 (later Vito and 'V' class).
646.
More noisy,
less economical,
unlikely to have a DPF,
higher tax, but registered as N1 (commercial) of no relevance.
Proven to be very capable of mega miles reliably.
651.
Quieter,
more economical,
less co2 output,
will have a DPF,
inherent problems with timing chain. Can show at above 65k miles or run for 200k miles no issue. A rattle at cold start up and chain, tensioner and timing gears likely need replacing, if the chain snaps, or possibly even if the chain jumps gears, bye bye engine.
Saving the planet is nice but not wanting to start the eternal debate in this forum again the DPF is a pain in't ass.
But I might still be tempted for a good motor.
The later van is likely to be less quiet w/o the 'comfort' interior. It does look to have auto lights, and possibly auto wipers?
It is cooler by appearance and should have daytime running lights at the front.
I prefer the tailgate.
We are likely to have very different requirements, but I don't want to drive a van that feels like a van. Even though it definitely gets used as one by me.
Our desire is to travel distance and not feel excessively knackered due to vibes, excess noise, or just plain driving a vehicle w/o some comforts.
If / when you get one you will be surprised at how you jump into it in preference to other motors. My 1st was a 2007 ex long Traveliner, bought at 296K miles as an experiment.
Cloth seats, till I swapped 'em, drivers seat heated. No steering controls, interior pretty much as your 1st example.
After a couple of months I realised I was jumping in that in preference to my 320CDI C class that was on the drive, and that was fully loaded.
As a more basic van I'm not sure I would still have that preference.
Take your time to get this right, there are a lot of potential dogs out there.
Type in the registration, as long as it isn't a personal reg you can often see where it was 1st registered. I steer clear of Scottish motors, and I am suspicious of rural mountain motors, they are more prone to rusting.
LX57R-- was registered in Sidcup, London. Doesn't mean it stayed there but it can be of some comfort.
Which you should go for, if either of the 2 you show us, is really up to you and your requirements.
But I wouldn't be afraid to continue your research. The market is quiet at the moment and I'm not seeing much new stuff coming up. How much of a rush are you in?
These Vito's can be very confusing with the wide array of options they came in / with.