I doubt you'll notice any difference between 260watts of PC vs 220 watts of VHO (which is plenty for a 55 BTW).
Out of curiosity, what T5 setup did you try on your 55? I assume it was a 4-bulb, did it have individual reflectors on each bulb (a near-necessity I hear). Also, did you use the stock bulbs that came with it or did you custom pick aftermarket bulbs? There's ton of discussion on this in the T5Q&A thread - it makes all the difference in both color output and PAR.