I'm all about trying something different and taking less popular units. In 7th, I never left home without my Razordons and giant Skrox block, despite their status as less than ideal choices.
Now, though, the salamanders really are too good for me to pass up. I've had games where two units of 2 literally accounted for the vast majority of my kills versus infantry heavy Dark Elf and WoC armies. The first time I landed a double flank shot against a Chaos Warrior hoard, I was sold.
I'd never hold it against anyone for not taking salamanders, and I can see why some folks would avoid them on principal- just like some other players don't choose Teclis, the Ring of Hotek, or Kairos because of their great advantage.
I hate bandying about the term 'broken' when it comes to anything with a powerful rule set, but salamanders are definitely up there as far as units that frustrate my opponents to tears. If a rival in a friendly game asks, I'll gladly swap them for Razordons, provided he is willing to make a similar concession.
I'd still rather face them than a dedicated gun line any day, though.