The "new" weapon profiles are pretty much what is already done in kill team. And it works just fine. But I think key to this working well is having a limited set of universal rules across all armies, which can be easily memorised after a couple of games, and then all you really need is just to look up the datacard/datasheet and nothing else, so not much different from just having a book for looking up rules.
I don't have high hopes for gw, as they are notorious for adding a crap ton of additional bloat afterwards, but for the stuff they've shown so far, I consider it an improvement over previous editions. And I don't really buy into argument such as "but previously you only had to look up the models bs/ws, then weapon profile and then add any modifiers" which in what way is better than having that bs/ws moved to weapon profile? For most part, end result will be the same as before, it's just different formating.
For the datasheets taking table space... Again, how is having a stack of printed out sheets different to having a physical book on the table? If you spread them all out then yeah, sure, obviously it is going to take more space, but that is no different to having printed out A4 sheets with unit profiles, weapon profiles, special rules, etc. I personally prefer to have a laptop with pdf's, as I find it much faster rather than flip through a book each time I need to look up a weapon profile which is on Page 987, then go back to 152 where unit stars are, and then go to a different book which has the universal rules, etc. Etc. Ultimately, I don't believe it is as massive a change as people are making it out to be, but each to their own.