I am the one, who loved old Mk 2 D way more. Yes, new is better in terms of firepower. But old Mk2 D was simply the only useful AS mech with JJs. That allowed to survive against LRMs, Arrows, LTs, bombs... No other assault was capable of it, really. 2*ATM12 were giving a great firepower with HSL as a back up. Also, the only big ATM+JJ combo. May be it needed something other in place of HSL (for better range brackets), but it was otherways fine.