Hello Chris,
In a very general way, floorstanding speakers are somewhat more critical in terms of placement than compact models on stands because of the greater bass output and larger front-panel area of a floorstander and its extension to the nearest boundary (the floor). But so long as you don't put one or the other in a corner (possibly the worst location for a floorstanding speaker--or any speaker, for that matter), the M50s should be reasonably accommodating to placement.
The fact that an M50 would be crossed over at 80 Hz doesn't really change the equation all that much, because upper bass, above the range of the subwoofer, can still interact with room boundaries and change the timbral balance of a speaker. I can't comment yet on the M50s vs. the M22ti's-perhaps someone who owns the M50s will post a reply--but the M22ti's are exceptionally open and articulate in the midrange and highs, with especially smooth string sound.
Regards,
