1 had an SL500 with the 273 and its low end grunt was lovely....not cammy at all
I agree, I very much enjoy the low-down torque of the 273 (have not driven an M113 for comparison but I assume it's similar). It's possible to drive all day without exceeding 2000rpm and still more than keep up with normal traffic on all types of roads. When wafting along on urban roads the gearbox will get into a high enough gear to cruise at 800 to 900 rpm and it has no problem pulling fairly rapidly from there without kicking down. 1st gear is generally never used, even for traffic light derbys where 2nd gear is still plenty fast enough, and 7th gear is so tall it gets 83mph from 2000rpm.
It all makes for effortless driving, with the knowledge that serious performance is available when required. It's not an AMG, the gearbox is definitely slower-acting, but it's still so powerful it's hard to find enough road to use it all.