Oversquare is when the bore is larger than the stroke, undersquare is when the stroke is more than the bore, and a square engine is the same in bore and stroke. The only engines I've heard called "boxers" in motorcycling are the flat twin BMW's.
What you've stated is true, though a bit over generalized.
What was done to your Sporty to get 138hp? I've got my Buell to 90ft-lbs and 100rwhp and it's fun as hell. It still has some in it, as I haven't got my hands on main jets big enough. What made you go IL-4?
I've looked at the 690SM and it's a bit too street oriented. My old-school ways make me weary of getting an FI bike, too...so the 690SMC is also out.
Spec wise the SM610 is the one to get. I put together a technical sheet of what I want and it's the only one that has it all. I've compared everything from engine technical specs to general chassis specs to fluid capacities and maintenance schedules to gear ratios and dyno charts. Professional and owner reviews have also been compiled over the past few years (I've been waiting a long time).
The Aprilia SXV is THE bike to have performance-wise, but I don't want to devote so much time in maintaining the thing.
The liter twins are too much. The KTM 950 and BMW HP2 are nice bikes...just too much of it.

I want something I can toss around, lay down, pick up and keep riding. I started on dirt bikes then bought a streetbike and am pretty much coming full circle.