If I had to keep it short, my problems with this mech would be, in order: Explosive crits, lack of range, excessive tonnage for ammo, and having no ammo-independent weapons. To expand on that a bit:
- The range isn't that impressive. 3/6/9 is OK if you are in the Inner Sphere, but in clan-land...that's pretty much brawling range, and 5/8 isn't necessarily fast enough to get you in range without getting shot to shreds first.
- the damage isn't all that impressive either. 8T of guns, plus 6T of ammo and 2T of Targeting Computer for a max of 48 damage. Oh, and 6T of ammo is 15 rounds of fire. Or you could use SRM's. 4SRM6's is 6T, you only need 4T of ammo to get 15 rounds of fire, and the max possible damage is still 48. Ok, so the SRMs will do less damage on average than the APGR's thanks to cluster rolls, but if we add two more so that the average SRM damage is 48, we get 9T or weapons, 6T of ammo, and you can use the left over ton for an additional heat sink to keep the design very close to being heat neutral, or use it for a laser weapon of some sort. That leaves you with only 6 explosive crits instead of 16. Or, you can just use the Crossbow B with 4 Streak 6's. Max damage is 48, range is actually longer, generates the same heat on a running alpha as the APGR's, and only has 4 explosive crits for 15 rounds of fire. Oh, and the streaks give you MORE potential crit rolls than the APGR's.
- Literally, the ONLY thing APGR's do better than other standard weapon systems is damage conventional infantry, and really, how many 2D6 rolls do you need to off a platoon of infantry? Honestly, three APGR's is probably enough to render most conventional infantry units either wiped out or so depleted they aren't a threat. The Crossbow has 16 APGR's. Just how often do you get so much infantry in one place, with such easy to-hit mods on the multiple secondary targets that you could realistically want 16 APGR's? You could slap on six or eight LMG's instead and still be able to reliably reduce two stands of infantry a turn while also having a bunch of weight and heat left over for better anti-everything-else weapons.
The massive number of explosive crits is a big part of the problem, but even if that were a more sane number boated APGR's just aren't all that impressive. Also, by using so dang many of them, you need a fairly crazy tonnage in ammo to match the endurance of other clan mechs, which isn't much to begin with. If you drop it down to four APGR's per arm, you get three tons back from ammo, four tons of weapons, and one ton less on the TarComp. That is eight tons for lasers and missiles, and you STILL have enough APGR's to murder more infantry a turn than you can effectively target. Throw on an ERPPC, or ER Large and a couple mediums, maybe a few heat sinks, and now you have a much more useful mech. Still not a great one, but a much less limited and one-dimensional one.