Tanking with <535 Def - Thoughts?Follow

(Please not this is ONLY for Heroics and doesn't include the ICC-5m - I maintain my full Raidtank spec and Def for anything challenging.)

In guild chat recently I said that I've started to drop Defense off of my Tankadin as I switched over to the "DPS Tanking Spec" that's discussed in these forums. I'm currently sitting around 515-525 depending on the gear choices I'm rotating in and out of... (In no way am I advocating dropping ALL def - just saying you don't need that magic number if you are in T9/10 type gear.) My basic goal is to increase my DPS and fun - while still safely tanking.

One guy was completely horrified by the idea. Like it was taboo or something... Personally, I'm looking at it more like taking a DPS class to an old Vanilla or TBC dungeon. Could the mobs kill you - yes, but probably not. I'm not T10, but even in 5m content I'm usually 41-42k after buffs. Even if things do crit on my - so what... Ouch 20k. It would literally take 3 massive crits in a row to kill me - (More like 4 or 5 if you include Argent Defender Procs)...

What are your thoughts? I think it's fun. It keeps the healer healing me (Mana) and I haven't noticed any change in speed. I ran H.VH this way with no problems (Not a great speed instance), but we did other things too. No stoppage - no slowness.

I tank heroics in half ret gear these days, most healers should be able to keep up

going slightly below isn't going to hurt