ATP3's have excellent warm highs, great mids and a tight bass, almost too tight for my liking. X230 have looser open ended bass, excellent but bright highs, decent mids. Haven't heard SRS-D2100. I'd recommend X230 over ATP3, unless you're into jazz.
The bottomline being, decide for yourself after listening to all 3. Don't take anyone elses opinions on speakers, not even mine.
PS: As ATP3's have downfiring mids, a good wooden table is a must. DO NOT get these if you intend to keep them on metal or fibre computer desks.
-Keith