I'd say so. If I had to make a list of best arena classes, I'd say:
1) Priest
2) Druid
3-4) Mage, Paladin
5-7) Hunter, Shaman, Warlock
8) Warrior
9) Rogue
Part of that list, though, is probably me not knowing how to successfully draft an arena rogue. I just feel like the class is too gimmicky to work out well in arena.
Warriors are alright in arena, but you definitely need to get a decent aggro draft. Fiery War Axe and Arcanite Reaper are a must since their only AOE is Whirlwind (which is terrible unless you have an Armorsmith) or Brawl. So you pretty much have to swing at things and take your lumps to keep their board clear.
Both Priest's and Druid's toolkit is varied enough that you can pretty easily get at least 5-3 even with crappy draws. But Priest's removal (Shadow Word: Pain and Death) are pretty much overpowered plus they have Mind Control.
Warrior deck flunked out bad, 1-3.
Then I drafted mage and went 7-3, solid but unspectacular.
Followed that up with a druid and went 7-1... then lost 2 games to absolutely ridiculous decks/draws. First a paladin who played 3 Aldor Peacekeepers (!), just rolling over me with the constant 2 for 1s. Okay, lucky draft and good draw, no problem.
Then I played against a priest. I had 4+4+2 attack on the board against his empty board, and a hand full of fatties. He mind controls a 4-attack minion, I trade and play a 8/8 treant. He mind controls the 8/8 treant. I play another 8/8 treant, he mind controls that too. 3 Mind Control back to back. I completely outplayed him in the early game, had an equal amount of late game cards in hand, and he just sweeped me with 3 basic cards. That feels so balanced. Sure, it's an 8 mana spell, but it's a guaranteed 2-for-1 even against other lategame cards, and usually 3+ for 1, with no obvious counters. Why is that a basic card again?
I'm guessing you face other arena decks with many wins when you get a lot of wins, or was that just random poor luck?
e: Arena 5, draft as priest, no mind control, no 7+ mana bombs. Oh well, 4-0 anyway because everything about this class is god damn ridiculous in limited. Northshire Cleric, PWS, Holy Nova, SWD, SWP, Mind Control are all stupid fucking good for basics, and even the hero power is pretty fucking powerful.