As mentioned in the Thunder thread, I'm a big Lao Hu fan, and I'd been waiting eagerly for the Thunder's younger brother.
Now, I'm not going to try and argue its a full on modern cavalry mech. One ER LL and the LRMs just aren't enough power at range to put it along side its many competitors in that class. But, once it passes 12 hexes, it becomes something special.
What I do like about the ranged weapons is that you've got a modern, high end heavy mech that isn't helpless beyond 9 hexes like the Thunder. No longer can you simply take a Griffin or a Valkyrie or a Hermes II can work away with impunity. Now, sure if you run into a Falconer you're in trouble, but that's scarcely a mark of shame. It also means you can shoot your way in, do a bit of damage to an enemy as you close. You're not much worse off than an old Orion for two turns or so.
Then the AC20 comes on line.
I definitely like the choice of the LB, especially with the deep ammo bin. Against a foe that isn't yet full of holes, slugs. But, more likely, your Vindicator and Catapult allies (not to mention your own weapons) have offered up some opportunities to use cluster rounds, and there's really no better weapon to have in such a situation. With the accuracy boost, you're not even unlikely to land those hits from 12 hexes out.
Yes, the Lao Hu is still a team player, like the Thunder. Yes, it does give up a bit of close in power from its lack of pulse lasers. But, it's other weapons come on line earlier so will still tend to do more damage over the course of a battle, and the cluster option and the range of the new canon make it both a better team player and a better solo hunter.
As to the variants, I've never had a chance to use the C3 Master. I can't imagine using it in a CC force, since they just don't have many C3 options, and most of their high end units use stealth technology rather than C3. If I were a mercenary or a Combine unit or something, it actually seems like a really delightful mech, since it's got some extra range. I'd have liked it to use the massed LRM5 option, since the idea of a massive of tiny minefields from T-Augs just seems crazy fun.
The GR model looks quality, but boring. GR, ER LL, LRMs. A classic medium cav mech. Probably really good. But, I agree is does seem like a refit, the sort of thing you'd whip up in a campaign where you had a small unit and didn't really need a specialist like the showroom model. For me, it's not something I'd go looking for, since it's not a 'special' but if I had one, I wouldn't trade it away.
Lastly, I really like the feel of the RAC model. Partially, I'm a huge targeting computer aficionado. I could case less about the RAC itself (I'm not a huge fan) but it's a decent weapon. I'm also not as in love with Plasmas as some folks. But, both have the same range brackets which makes the mech pretty easy to use, and you get some pretty solid power with pretty good grouping at 15 hexes with solid opportunities to hit (especially since these will usually go to better pilots). I wouldn't characterize it as overly Thunder like, since I think there's enough added capability in thouse extra six hexes of range, but I agree it's less flexable than the base model with the ER LL and more LRMs.
Lastly, the stealth/GR is just another of many similar mechs. Quite good, and I wouldn't turn one down if offered. But neither would I probably request one, unless I suppose I was putting together a stealth cav lance. I can't think of four other mechs with that sort of speed, range, and direct fire power (not LRMs, which are quite common on stealth mechs) on a stealth platform, so I think I'd be more apt to take the last variant, if I were of a mind to use a mech like it.
Of course, one of the things I've always liked about the mech is the story. The idea of a big company making a mech they think is just fine, only for a young MechWarrior to realize that they were full of it and could have done way better, is both delicious and ever so plausible (especially in the context of the BT universe and it's litany of substandard designs). Its the story that so many of us have told ourselves over the years: "look at that mech. I could have done so much better had it been me." Now, we all know from a real world stand point that most of that is absolutely intentional, that most designers try explicitly to make 'interesting' designs. But I like that they're also self aware enough to, at least in this mech, acknowledge that in universe. Though, do we know what became of the young lady in question? We know she got a spot in the Capellan Hussars regiment from Victoria, but I hope she made it through the Jihad already, made something of herself.