Although I've never driven an E46 (M, regular 3 series, 'vert, or otherwise), I've owned my E93 for almost a month, and it is truly amazing performance wise. I agree with The Bry's post above, the only people who seem to have a problem with its weight, handling are people who compare it to the coupe/sedan, which is quite frankly a ridiculous comparison. The car is immensely more fun and fast than any of those reviews suggest, and the vast majority if not all posts I've seen on this forum and others criticizing its performance come from people who have never even driven it.
Believe me, you can drive this car very hard, the acceleration/handling absolutely kills the vast majority of most other (and much lighter) cars out on the road, and I've never heard or felt any of these so-called "cowl shakes," rattles or squeaks - I've driven other convertibles which do have squeaks or have noticeable cowl shake over bumps/hard turns - but my E93 has not even slightly displayed such behavior.
I've also driven a stock E90 335xi (yes, sedan, not 'vert, and supposedly the xi accelerates faster than the rear-drive i) and the E93 feels
much faster acceleration-wise (according to Edmunds, whose 0-60 times seem slighly slower than other sources, 0-60 with M DCT is 4.8 from dead stop, 4.6 with the one-foot rolling start most American car magazines use (vs. 4.8-5.0 for stock 335i coupe/sedan, presumably with 1 foot rolling start). And if the E93 M3 feels much faster than the 335xi, I can't imagine the huge difference between it and the 335i 'vert (by the way, I think I'm speaking on behalf of all E93 M3 owners who are tired of hearing "oh, if you want a 'vert, you should just get the 335i" - what a bunch of crap
- just look at fastestlaps.com for the Autozeitung track where the E93 M3 completely killed the 335i, outlapped many other non-convertible cars on that track, Audi S5, E60 M5, several non-convertible AMG's, was very close to the RS4 sedan (on another track on fastestlaps.com, it also outlapped the CLK63 AMG vert and RS4 vert - imagine how huge the difference would be vs. the 335i 'vert)!!! [By the way, I honestly don't mean any offense to stock 335i owners - they're fantastic cars, and while my comments might sound arrogant, stock 335i to M3 is an apples-to-oranges comparison, so I don't think this is a "rip" on the 335]. Don't you find it interesting that none of the naysayers back up their criticisms with any lap times that are currently available, particularly when the lap times are better than so many other non-convertibles?
I've also driven the E92 6MT (which I kept under 5.5k rpms - and under 5.5K on public roads, I could not perceive any noticeable difference in acceleration/handling). I have no doubt the coupe/sedan are in fact faster, but if you combine the drop-top with no
perceptible difference in performance on the street, who the heck cares if it's a few tenths slower - particularly with no squeaks, rattles, shakes, or that other nonsense I have yet to experience driving the car pretty hard myself!!
Finally, I've driven a 2005 E55 AMG - and I swear my vert feels only slightly (but barely) slower acceleration wise.
I cannot imagine how you'd be disappointed with the performance of this car, especially with the revs at 4k or higher - it is a beast!! I know you're interested in 6MT, but if you're crusing at 55mph in S5 in third gear and hit the gas, it WILL slam you back in your seat, notwithstanding all the "portly" comments the car gets from reviewers who insist on comparing it to non-convertible performance cars - if you test drive this car, you'll also be wondering what the heck these reviewers are talking about suggesting its performance is lackluster or somewhat disappointing - sorry, but a complete load of crap based on my experience.
I agree with the other posts above, as I would have huge regrets not being able to drop the top, and no regrets sacrificing a performance gain that in the overwhelming majority of driving circumstances would not even be noticed.
Sorry again everyone, but I can't let people keep kicking the E93 around when the evidence and personal experience show that it deserves far more positive recognition than it has been getting. GET THE 'VERT!!!