I share your worries about the current Jazz, but I can't call the Williams/Boozer era "contenders" either. In five years, they made the playoffs 4 times:
2007 - made us all think they were contenders by beating a weak Houston team (give them credit for doing it without homecourt) then beat a Golden State team. This landed them in the Conference Finals, and we all assumed they were contenders, but when they met a real contender (the Spurs), they were done in 5 games.
2008 - again, give them credit for beating Houston without homecourt, but the Rockets were missing key parts. When they met a real contender (the Lakers), they lost, but at least they made it a series, lasting 6 games.
2009 - Jazz slid into 8th place down the stretch, faced a real contender in the first round, and lost in 5 games.
2010 - Same story, only they were swept.
In the regular season, they finished without homecourt all four times. Once there, they took advantage of a weaker Houston team (twice) and Golden State's upset to look like contenders, but they never beat anybody of any note in the playoffs. I think they were pretenders, not contenders.