first, don't know where you live since you don't post it, but you should get quotes for the 23GSX and the ROO 23SS from RVW, since they sell them both and have some of the best prices in the country.
the Roo and Shamrock are twin brands and you'll get much better prices on the Roo 23SS, than the Shamrock 23SS.
the 23SS also has ducted a/c, which is superior to the blast from the center a/c that the 23GSX has.
don't know the the 23GSX has the pre-attached canvas, like the new 23SS's have, which many feel is a better setup. also, i think the bench in front of the front bunk is a waste and something you have to crawl over. it also takes up floorspace.
it also seems that the 23SS has more inside storage and kitchen counterspace.
but the Coachmen has a tub instead of a corner shower, so if you have little kids, that would be an advantage. also, you can get diamond plate for the front.
Coachmen only has one year factory warranty, whereas the Roo/Shamrock has a 2nd year factory warranty for an extra $150.
and Zoe the Wonder Dog(R.I.P.)
'07 Roo 23SS pushing an '07 Chevy Avalanche
Equalizer WDH and Prodigy BC