i like the sr series personally. i have a 505 and it does a great job. although i'd prefer a P/J pickup styling. but the soapbars do an alrite job..
Grammar and spelling omitted as an exercise for the reader.
I second what Kivarenn says, the SR/SRX series are nice god damn basses, though I've never held any of their 5-strings before.

Sorry for the cookie cutter response but.. Play both at a store and see what you prefer, though I'd probably be more leaning towards the 355 myself..
Both are nice basses and its going to be a matter of which one you prefer as Haanz has said.
Their 5ers are quite nice, but I find the string spacing a bit tight on them myself, so I would recommend you play one before purchasing.
I had an SR and an SRX before and I preferred the SR. Neither were 5 stringers though. The SRX seems to have stronger pick ups and more suitable for rock. It seemed like I could get a bigger variety of sounds from the SR. That's just my opinion...I like both.
Fender Geddy Lee, Precision (MIA), Fender Standard Jazz, Ibanez SR700, GK MB210 combo, GK 210MBE