Sounds like the MX-5000 could be worth a try. My MX-1200 is paired with an MSC-400 and it works pretty darn well (I don't seem to have too many missed commands although it does happen more than I'd like). To which settings in the MX-5000 are you referring? Pickup sensor? Some other setting that maybe doesn't exist in the MX-1200? Also, what do sleep timers have to do with improving the MX-5000's performance (I've never used a sleep timer).