This is the first Heyawake on this site that I've managed to solve. After quite a bit of difficulty, as well. It was enjoyable.Now, if only the rest of your puzzles (more specifically the Masyu and LITS) were this difficult.
Thanks, though I'm surprised - in testing I found this harder than Puzzle 151 (Four by Four). Without giving too much away tune in on Tuesday at 19:00 (GMT) for a difficult Maysu with a surprising solution.
*Tuesday 12th (not tomorrow!)