I was going to do the same thing (upgrade the fronts to 11Ls), but, having heard both, I atually preferred the L-ites.
If you were just buying a pair of speakers for stereo listening, the 11Ls would probably be better. The L-ites are a little light on bass, the 11Ls go a bit lower. This isn't really a problem with the full set, since the sub provides all the bass you'd ever need.
Where the L-ites win is at the top end, due to the uprated tweeter (which will be fitted to the 11Ls at some point in the future), and the improved imaging ,due, presumably, to the narrower baffle.
Ask your dealer to demo the speakers in 2.1 mode first, and see if you can get him to not tell you whether you are listening to the L-ites or the 11Ls. That's what my dealer did. It was the first time that he'd heard the L-ites, and he was convinced that he'd connected the 11Ls!
EDIT: just spotted your edit!