Power Cycle count is 137, yet Unexpected Power Loss Count is 156?! Makes me think HDTune isn't properly decoding the SMART data.
2 reallocated sectors is NOT terrible in 638 hours of use (but not great either, unless you've been endurance testing). I'm guessing at ~90GB of Total Host Writes, which is 1.5x drive size, so should cause (a minimum of) 1.5 p/e cycles, ie 2 out of 3,000-10,000 - so nothing to worry about yet. Dunno why HDTune is warning you about minimal wear.
CDI is far more reliable and says 100% good, I'd go with that. But check with other apps too (eg SSDLife), don't OCZ have their own toolbox/status monitor?