Okay, I think two updates ago the C8's explosion radius got larger. I dunno, maybe twice the size. At first glance (or to a non-BA player), this might seem like a positive change because 1) It's more likely to hit other armor components with splash, and 2) It becomes SLIGHTLY more useful if planted on the ground or walls. I didn't wanna panic at the time and be like "ZOMG WTF IS THIS," so I gave myself time to adjust and wanted to be sure this wasn't my imagination.
Months on, though, I still think this is actually a NEGATIVE change. The fact of the matter is that the second positive attribute I listed is still absurdly circumstantial (even moreso by a huge extent than Inferno Charges and thrown NARCs). The odds that an enemy mech will be standing by a wall that you CAN stick C8 to but somehow you aren't able to stick it to the mech itself are astronomical. For killing other BA, the explosion still isn't very useful, and Inferno Charges are a mech better choice. Mechs move too much to attack their legs with C8. As for the first potential positive, I haven't really noticed myself killing mechs faster with the larger explosion radius.
The real problem is that it has become a lot easier to kill yourself with C8, and
a lot less predictable. Since the new updates, I've been right underneath C8 and taken no damage, and I've been 10~15 meters from my C8 and been instantly killed. The only "safe" way to throw C8 is to walk out to about 16~20 meters away after throwing a single C8. Throwing 2 C8 in a row will means you'll be sticking around too long while the first one's timer is counting down, and have a higher chance of being blasted away. By contrast, in earlier builds you were safe from the explosions at a good distance for throwing them. This isn't made any easier by the approximated hitboxes used for C8 (throwing a C8 at a mech's arm might have the C8 floating a meter or two away from it randomly).
I guess the "fun" part of the new system is that you have to run so far away from a mech after throwing just one or possibly 2 C8 that you are in the mech or vehicle's sweet spot for killing BA; the safe distance from C8 is the BEST distance for mechs and vehicles to kill BA at. Another way of avoiding this problem that's only really possible on tanks is to jump over it repeatedly, attacking opposite sides of armor. Of course, especially since the introduction of the new hull system, this is the absolute worst way to attack a tank, it draws TONS of attention to the BA, it makes it a lot easier to get run over, and it leaves you completely vulnerable because it consumes your jumpjets and jj=life for a BA. You can kinda do the same thing against very slow mechs, but again it's a bad idea.
Now combine this with the [M]ap C8 bug, the weapon-changing C8 bug (which for me has significantly worsened since the last patch), and the BA SSRM bug (all of which I really hope will get fixed eventually, but seem to be underestimated in importance). There's too much to think about and too much random chance when in a close-range conflict as BA. In this range, quick reaction time and reading an opponent are essential. Now imagine doing that while shuffling around the keyboard with time-consuming (changing weapons takes a few seconds, the M key is far from ASDF) workarounds that you can only guess at. All of the while using the missiles is not an option unless you go airborne, which makes you an easy target. And of course combine that with the new hull system, which makes all vehicles much more durable, and the internal system planned for mechs that will do the same. It's only becoming harder to deal damage as BA.
Now I'm not the best BA player. However, I asked the best BA player, and he hasn't been playing much BA recently.

Another good BA player didn't respond. So hopefully some of them will respond and tell me if I am totally off my rocker or dead-on.
The real question is, was the C8 explosion radius increase meant as a buff or a huge nerf? Because it's the later, IMO.
Also, since the internals/hull system are straight-up buffs to mechs/vehicles (as in, it's always a positive, never a negative), will BA ever see a straight up buff (not different options of suits that have different strengths and weaknesses). What about aerospace? Will they ever see a straight-up buff?
Also, sorry if this topic came off as whiny. I know it's
MechWarrior. And yes I know this is a beta. But if you're gonna go for combined arms, you shouldn't just let problems continue to stack up for one of the "arms."
Again many thanks to the developers. I know they are working hard on this and it's hard to foresee how one chance will affect something else. And I'd say that overall, the game is stronger now than a few months ago.