I had the 602's, the monitor version of the 602.5's. Yours are probably more bass capable than mine, given the longer cabinet. But I did run mine with a matching sub and was very happy with them. Given that people run subs with floor-standers costing 10x as much, that is probably the best upgrade route - there is no better way to get bass. That said, listen as far and as wide as you can. Though I have made all my purchases with little if any comparison shopping, and turned out very happy, it can only lead to a better (albeit more difficult) decision.
And once you make a decision, curl up next to Significant Other Cohabitant with bottle of spirit and show her how good Journey sounds. :|
And once you make a decision, curl up next to Significant Other Cohabitant with bottle of spirit and show her how good Journey sounds. :|