You would have to ride each and compare for yourself. These guys just love to jump on anybody that's not riding a superjet. If you really want to start playing and throwing your ski around, I'd suggest that you try out a superjet, you may find it just suits your style better. I don't regret buying my SXR but i do have 3 SJ's now and am always looking for more and I'm not looking for any more SXR's.
Yes, the SXR has a stock siphon style bilge. I do subs all the time and only have the stocker plus a duckbill drain and have never had any problem with subs. Fountains however are a different story...
Adding an electric bilge would be an excellent idea for added safety and probably considered mandatory by most. If you want to go single, go with at least an 800gph. If you like doubles then 2 500's are good.