Character Generation is slightly faster in AToW than it was in 3rd, but only slightly. It's still fiendishly slow, and could really use a program for making character sheets. I've run into a few people making Excel sheets for the job, but rarely do said excel sheets actually WORK. They're frequently WIPs.
Admittedly, though character building is slow the most time consuming part is deciding on equipment. If you have any less than 3+ TP, You only get access to the most rudimentary of gear, but once you get 3TP, you're suddenly overwhelmed by a plethora of choices. You go from only having access to basic slug-throwing pistols, double barreled shotguns, and hunting rifles, to being able to purchase Gyrojet Carbines and Pulse Laser Pistols in a very short period of time. The good part about AToW is that unlike 3rd, all that gear is compiled in one book instead of being scattered haphazardly in every scenario book since 1999. However, that blessing is also it's curse, meaning that if you've only got equipped 2, you're combing through the book saying "Alright, what can I take?".
But once chargen is said and done, AToW acts just how I think a Battletech RPG should. It's a very simple, rudimentary system, though it's incredibly deadly if left unmodified. Players can easily bleed out and die from the simplest of firearm wounds, and nothing short of the heaviest armor offers significant protection from firearms.
But like I was saying about simplicity, It's less realistic than 3e, but it eliminates the wounds system for a simple HP system, and eliminates the need for rolling damage after rolling the hit, as the success margins of the hit dictate the damage dealt.
Overall, the only qualm I have is that for whatever reason, Herb took all the Battletech mods and flipped them on their head, applying it to the die roll, rather than the target number we're used to. It's in essence the same system, but throws existing players off balance, seemingly with no reason other than the priorly stated "Because we can't just be the last game"
Long story short, while AToW isn't much faster for character construction, it's a simpler system that works excellently as a tandem product, going back to the 2D6 system to make the transition to Mech Combat all the easier, and not having so many rules as to overwhelm players who've never played Battletech before while they play both games in tandem.