Anticipation, Accurate, Intuition and Snare Gun synergize so well together it's really not funny. Unlike other good shooters, he has something to do in a game against Reeikan or Wedge (especially Leia/Wedge). For me, in games so far, he has served three purposes.
1) 20, 30, or 40dmg attacker (used Han RH, Whorm, Republic and Sith so far). This is by far his minor use, but he has a pretty reliable damage output, especially if you either up his attack by 4, up his damage, increase his number of attacks (extra or twin), give him fps for rereolls (and mettle) or several of the above.
2) Lock down a key attacker, or big nasty from the opponent. So far, in three test games my Zuckuss has done the following. 1 - Locked down Dean's 4-Lom the entire game until he was dead, mostly from Zuck himself since my Han RH couldn't hit anything. 2 - Locked down a Ferus, preventing all but one attack made by him all game. 3 - Turned Kyle BM into a gambit collecting turret while I eliminated the remainder of his squad. The Sith last night absolutely owned the NR, in large part thanks to Zuckuss. Who would argue that the Sith are better than the NR up to this point? It didn't even matter that Zuck spent most of the game doing 0 damage. I simply kept Kyle from doing anything the entire game, and eliminated his other pieces one by one. First it was Jarael, then Kol, then TBSV/Wedge and finally Leia. Poor Kyle collected like 40-50pts in gambit, but I don't think that was my opponent's intentions
3) Commander hunting. Most people run intuition poorly, but when done right, it's incredibly hard to protect commanders from a figure with it. Further, with Zuckuss, commanders can't take pop shots at all with out severe risk. I bring up an example from game 2 (Seps vs Rebels). I finally let Ferus go after taking most of his hps (finished him with the new Bossk that round anyway). My opponent's Reeikan had to come out of hiding to take out a key ugo/mouse (don't remember which) I was using to block a much nastier Dengar Final Shot. Dengar got his final shot, and I in turn locked down, and then out Reeikan. You don't get to run away because you took too much damage and hid in the back against Zuck. Once you are out there, your opponent can lock you down.
Zuckuss is an amazing figure, and he fits with virtually every faction in a variety of ways. You can either use him completely as support, add a CE or two (most of the ones that he will benefit most from are already in good squads), or max him out (I've not tried this yet). He works very well with extra FPs, which the Rebels, Sith and NR can do for cheap. The FPs can be key to make sure you have 2 attempts per turn to lock someone down. Extra attacks work best with twin in Seps, and Flobi/Exile in Republic and OR and Bothans in the Rebels. Getting that key +4 is pretty easy in Sith (Malak), Rep (lots of options, Qui-Gon being the most obvious) and so on.
As to which factions can use him best? I kind think it's all of them for the strategic player. For example, Vong, the faction on the surface it would seem he synergizes the least with. What is generally a Vong's biggest threat? Disruptive. What happens to disruptive when it gets stuck in place outside the battle for most of the game? Answer - it doesn't help.