I was going to post the same question myself but under the heading "I'm sure you'll think I'm crazy but . . . "
However, I am seriously thinking of going for this new issue of the advanced but ill-fated Acela if somebody from Lionel (or a dealer who can find out) will answer a few questions (the dealer who answers first gets my order if I go for it):
1. What are the differences (if any) between the software controlling the new model and the original? A Legacy CAB-2 has Acela controls built in but unfortunately on shutdown the pantographs don't automatically retract as they do under CAB-1 control. I assume that the new one will come with a Legacy module but is there any other difference? It's also advertised as having a quilling horn and I assume that means there's been some software revision.
2. But this is just part of a more general question, which is exactly how far the operating issues of the original have been addressed. There's no tilt feature in the new model, which I assume means that it was thought too problematic to rectify. Fine - if that cures other problems. (I wouldn't miss the tilt feature as I could not detect any tilt in my set except in "demo" mode while it was standing still, when the tilt and accompanying sound worked perfectly.) As for other problems, I have the original set and the add-on passenger cars. Three out of the six cars had operating difficulties straight out of the box, mainly to do with failing to reset properly once the door opening feature was operated, leading to the lights under the doors flashing to signal that a reset was required. A reset however just never worked and it's very unsatisfactory having to lock out the door opening feature on one side of the car to stop the lights flashing.
3. The catalog description does not refer to the cars having the door lights which illuminate when the doors open, which is a neat feature; has that gone too?
4. If you look very closely at the catalog illustrations one of them appears to show that the couplers are the same as in the original, which absent some other improvement in the model is not good news, IMHO. The couplers were said to be the source of about 80% of Acela operating problems. I think that unless you have a large and dead level permanent layout on which to run this beast the coupler alignment and the infrared contact through it is bound to fail at some point. I once had the wild idea of trying to replace all of them with Lionel steam engine wireless tethers, which I have never had a problem with. I never got that far with trying to get the whole set to run consistently.
5. Are the cars in the new add-on pack compatible with the original sets? If so I might get a reliable five-car consist going although I guess that the tilt feature in the original cars would have to be locked out even if it does not work when the train is in motion.
6. Generally my worry is that the new model is a reissue with the tilt mechanism removed or just disabled but nothing in the way of real improvements. Pity as the passenger cars are otherwise hands down the best modern ones I have ever seen in O gauge, including GGD's 3-rail offerings to date.
7. Anybody who would shell out for the new version of the Acela must be a dedicated Lionel fan so there's good reason why updated and detailed info about this model should be volunteered by Lionel now at the pre-order stage.