SRWK: Finished today. Time for tl;dr thoughts.
The cast list was terrific; everything except Mazinger Z is in only its first or second appearance, meaning lots of fresh units and maps. Seeing all the new skills and systems was quite interesting, there's some nifty ideas in the game that I'd really like to see become SRW regulars.
Animation was quite nice, with even more dynamic kills than SRWW, and the music was terrific. Shangri-La, King Gainer Over, Can You Feel My Soul, Zips, Stormbringer, Yotaka no Yume, Engage!!! Godannar... the list just goes on and on. Quite a few of these I even preferred to the original version, as they replaced middling to bad vocals with some really nice synth.
The PU system was the main gameplay update, bringing squads to handhelds in simplified form. It worked well enough early on, with lots of reasons to pair units up and some to run it solo, but the balance just breaks down past midgame. The first problem is enemy support defense; almost every grunt comes paired later on, and having to deal with support defend on almost every single attack is really annoying. Chain attacks are your only form of ALLs, so you use them on almost everything with the necessary skill levels and not totally crappy C weapons. The second is that level 2/3 of chain attack is broken in this game, hitting 4-6 grunts for near-full power and only risking counterattacks from one of them.
Terrain ranks matter far more than they did previously, which is nice overall. The standard terrain modifiers are A rank and the S rank versions are late and really rare, which actually gives S terrains a lot of value. The only downside is that a lot of entire casts only have B in Space in this game, which means they can't hit or dodge worth a damn without a thruster module. With the final stage in space this limits your units somewhat; it's the only reason I didn't use Volkein Kai for instance.
Spirits and SP commands had some issues in this game. The universal SP costs that the (non-OG) handhelds use isn't as good as the pilot-specific ones in OG and PS2 games, but it was bearable in J and W at least because you had plenty of SP. Here... well, early on it's not too bad on combat units since you don't need (and don't have) Valor, so you can use all your SP on Focus, Alert/Invincible, and the occasional Strike, none of which is too pricy. Even when you do start picking up Valor (at an overpriced 45 SP) you rarely need more than one shot on a Jeeg or Strike Freedom to gun down a fleeing boss for a good while. Lategame though, bosses start getting pretty durable (while still being damaging), and the nobody besides the multi-pilot units has enough SP for more than one round of Valor+Alert/Invincible/Sense. Hell, even at endgame I had quite a few people who lacked the 90 SP needed for two uses of Valor alone, which was -_-.
Support spells are a problem from the start. For starters, you never really get a whole lot of them; for nearly half the game you have one shot of Bless off Sayaka, two shots of Cheer off Tsubaki and Lulu (who takes a few levels to get it), and nothing more. Had to feed Sayaka all my SP Up/Mental Focus parts for a long time to get her a second use of Bless. Lacus joins on the Destiny finale with both Bless and Cheer, and Tsubaki/Lulu get Bless eventually, and that's your entire supporting core for almost the entire game. That's annoyingly scarce, frankly. As for the more obscure stuff like Enable (90 SP), Hope (80 SP), Renew (60 SP), Disturbance (70 SP), etc., those are obscenely rare and extremely late if you even get them at all. Even if you do you'll only be able to use them once before running out of SP due to the 85-115 range endgame SP pools.
On the whole it feels like Banpresto took a lot of your options away in terms of using SP, which is just annoying if not gamebreaking game design. Early on I thought that extra deployment slots from the PU system would compensate just fine for neutered SP pools like they did in Z, but max SP just grows too slowly and you don't get enough pilots with non-combat spirits and then you don't even use partners all that much lategame, although babysitting a support unit was one of the few ways I did.
Challenge was a bit uneven, but overall it was easyish without being completely mindless so you had to pay some attention still. There were a few poorly designed maps but on the whole I thought Banpresto did a decent job here. The Stargazer map was one of the more interesting base defense missions I've seen in an SRW game.
Overall, the game feels somewhat unpolished, especially compared to W, but still solid. Xer's 7/10 feels like a fair score here.
Unit evaluations tomorrow, this post is getting rather long already and I need to stop procrastinating on some studying.