Whats your boot size... you say your 5'10 so you gotta be careful you don't want to much over hang. 155 length might be better. but its all up to you how small you want it man.
I wear a size 10 boot so i'm not to worried about having over hang. I think im gonna go with the 152 so it'll be a bit more park based.
The Salomon Relays are nice bindings riding wise. The biggest problem with Salomon is that their buckles are not designed to last. I have a pair of last years Relays and the buckles are shite. Constantly locking up and being a general pain in the arse to get out of. Salomon doesn't seem to like to take input from the everyday user, just their pros. Who are replacing their bindings after a month of two of use, vs a season. That reason alone has me shying away from buying their bindings. Rome and Union both have quality buckles that operate butter smooth.
Well it kind of came down to either the Ride EX or the Rome 390s. The reason why I'm considering the EX's still is cause I found them for a really nice deal and the 390s are an extra 30 from what I would be payin for the rides