Welcome, Michael!
If you like the idea of OB, have the space, and already have the dual subs to fill out the lower end, if budget allows the X-Statik is A LOT of speaker for the money, and as many have said here arguably his best bang-for-the-buck designs out there right now. The X-Statik is listed as having a lower cutoff of 60Hz, which is going to be gradual in-room as that cutoff is coming from a sealed box low end. The X-LS Encores, on the other hand, play down to the mid-50Hz range solidly but drop off fast from there, in this case because the woofer is in a ported box.
I've had the X-CS before (sealed MTM design using a pair of the M165 woofers) and still have a pair of X-LS, and with a pair of sealed subs I found that I actually liked crossing over the sealed speaker at 80Hz (rather than 60Hz) because for my tastes at the time I got a little more meat on the bone in the lower midrange with my subs doing some of that work (sounded a little lean to me crossed over at 60Hz, but keep in mind that was in a medium-biggish room that was very well treated for bass and I was using a pair of sealed GR-driver servo subs, so I was confident in keeping the sound quality up in that range in spite of using subs).
With the X-LS, I always seemed to struggle to get them to blend such that I was happier with them with subs than without. This was with the same sealed subs, and probably the best integration I got was either at 60Hz or 40Hz crossover depending on how I fiddled with the other settings on the sub plate amps, but if memory serves right I either felt like the subs muddied the sound of the speakers if crossed higher (80Hz-60Hz) or overpowered them (60Hz-40Hz). Not saying it can't be done (and I would venture again the best crossover point would end up lower than a sealed bottom end speaker like the X-Statik), but in that room at that time I just couldn't sort it for myself. For what it is worth, I ended up settling on just a pair of X-LS by themselves for a time in that room and was content, but contentment and bass for audiophiles is a very subjective thing, so YMMV.
In your case, based on your initial thoughts, I'd probably go X-Statik and not look back. With your subs you'll have a great foundation for a system that can grow with you in a lot of different directions without the speakers becoming the weak link.
Hope that helps!
