While I bear Epic no ill will, but I am more than happy to wait a year to buy the game. Battletech games no longer hold the lustre for me they once did, particularly the MW titles. This game has it's issues, they've been discussed ad nauseum, but better than MW3/4 at release? I'm assuming you're speaking absolutely here, not relative to other games of the day, because the AI in MW 3 and 4 were both pretty good for their time, there appears to be no increase in squad control functionality, and there's less variation in terrain and mission type.
Sure the graphics are pretty, being able to destroy buildings is great, etc, but the AI is horrendous, squad mates are idiots, and the interior of the dropship is about as interactive as Madame Tussaud's. Underwhelming is the only way I can describe it. The most bemusing thing for me is that the gaming press have bought into the notion that this game must succeed of we lose MW. If the MW franchise can survive MechAssault 2, it's the cockroach of franchises, and will be here long after we're all gone.
For terrain I can't speak much to MW4's expansions, but compared to the base MW3 and MW4 games the difference is considerable. MW3 in particular suffers from the utilization of static one-off maps, and while these hand-made maps are sublime, they want for variety. I'll cop that MW5's would benefit from roads on the maps, but in terms of style I think they serve their role adequately. In nearly 40 hours of play, I have rarely encountered a strikingly similar map (I'd note that I don't think the base MW3 and MW4 games would have even even given me 40 hours of play in the inaugural playthrough). Frankly, when playing I generally ignore the dropship interior (your Madam Tussaud's analogy is apt).
I'll admit that the AI leaves much to be desired, but I'd argue this was always the case in the MechWarrior franchise. MW5 at least offers the possibility to bring additional human players into the campaign (granted, this can make it considerably easier, but it wasn't an option at all in MW3 and I seem to recall MW4 not being able to do so without mods, correct me if I'm wrong). MW3's AI was never outstanding, though I'll admin I don't have enough experience with MW4 to judge the AI.
That said, I'm not at all in the camp that the game must succeed; I think it does on its own merits. By all means, wait to buy the game. I'd argue that if the franchise ended here, and never saw another PC game, we would not be worse off, than if it had never existed. With mod support dropping sometime between this week and next month, I'm fairly confident that the community could build a lot more from the foundation of MW5, than any of the precursor games.
A small lifetime ago, back when I played MW3, I used to fantasize about the possibilities that MW5 now offers: cooperative multiplayer campaigns, my run of the inner sphere, the ability to dynamically drop with my friends, to serve the various lords of the successor states as I saw fit, all while playing in an era where heat management really mattered. To me, the beauty of MW5 is that it offers all this, and serve as a springboard to so much more moving forward, be it in the form of official PGI expansions or community mods. Sure, it's not perfect, but the series never was, and this has come closer than others.
