Send it.
I definitely vote for you to send it in. It's a really good looking level, and for the most part, it plays very well. Just make a note in your readme that it's a very processor intensive level, and those with slower PC's, even with substantial amounts of memory, may have trouble with framerates in certain areas.
If you've watched the reviews being posted on NaliCity, you'll see they get a lot of maps that barely rate a 1 or 2, on a scale of 10. Yours is at least a 9 on looks and design. They may knock off a point for performance, but then, they may not. It certainly looks like one of the better user-made maps I've seen (I'm new to level designing, but not to playing).
Besides, they may even have one or two reviewers who know enough on the technical side to spot the cause for the slowdown which we seem to be missing. They seem to make an effort to provide some feedback to the mapmaker.
Pal