I'm not sure of j_garcia's personal experience with the LSiC and the RSC200, but I would definitely say that the comment of the LSiC being "nowhere near as good as the [RSC200]" is an exaggeration.
Is the LSiC a matching center to the Rockets? No. Of course not. And in terms of sound, it is more forward and less accurate than the Rocket center. But to say "nowhere near as good" implies a far greater difference in sound quality than is supported by actual listening.
Simply put, I maintain that the LSiC is a good choice for this situation. Here, we are limited mostly by physical size requirements. So we first look to meet the physical size requirement and then look for a speaker that matches the sound qualities of the Rockets as closely as possible. We cannot expect a perfect match, but we try to get as close as we can.
And in my listening experience, the LSiC comes closer than other center speakers that would physically fit into the available space. From top to bottom, the timbre is not the same as the Rockets, but with a center speaker, I consider the reproduction of the human voice to be the most critical factor. The tweeter is largely responsible for the majority of human voice reproduction. Towards the lower registers of male voices, the midrange drivers and cabinet design start to play a larger role, but for the greatest portion of the human voice, it is the tweeter that is reproducing the sound.
Obviously, the solution for Green_Flea can only be decided by Green_Flea listening with the speaker in his own setup. But to dismiss the LSiC out of hand would be a mistake IMO. It may not be acceptable to Green_Flea - that could definitely be the end result. But IMO, it is worth a try and, in fact, I believe it to have the best chance of meeting Green_Flea's needs while retaining a decent match to the Rockets' audio qualities.