So how accurate are the mechanics to the tabletop? I've only played tabletop a couple times but I don't remember stability or "evasion points" or a lot of this stuff. To be honest, 'adapting' it to the video game takes some of the fun out of it.
I feel like it does an adequate job of capturing the feel of a lot of the table top stuff, but it's definitely its own system inspired by the tabletop and taking a lot of cues from X-com Enemy Unknown. Just for starters damage and armor numbers have been multiplied by 5 to allow for smaller balance tweaks, and accuracy is given in percentage hit chances which are not, I think, based on a 2d6 roll in any way. Stability damage is a good example of one of a few changes that make the game more deterministic: Instead of pilots making a Pilot Skill roll when they're hit, instead they take stability damage and fall down when they take more than a certain total amount, which is determined by the pilot skill. Another big example is initiative isn't determined randomly. I honestly think this is for the better, having some of that stuff be super random like in the tabletop isn't really conducive to a game with a long campaign and long-lasting consequences to mission outcomes. There's also a lot of edge-case rules that have been simplified, for example weapons on arms don't have a different firing arc than torso weapons and there's no mech sliding, no adding up defence bonuses from multiple tree tiles, etc. There's also a light system of special character abilities which is very reminiscent of X-com.
All of that stuff, though, I think serves it well as a video game. The only thing I think you're going to dislike if you're a TT fan, and it is a big change, is that you fire weapons immediately after moving, rather than everybody moving in order, and then everybody firing weapons. This means that there's not really any outmaneuvering somebody bigger and making it totally impossible for them to lock weapons on you. In one of the dev blogs they even talked about how it would be very confusing to represent visually, with mechs taking damage but only blowing up later etc which happens in TT. There's corresponding balance changes to make light mechs not worthless and I still think the game is fun, but that's the biggest unique "Battletech" thing that's missing. If you can get over that then the other stuff shouldn't be a problem.