Ed, the newer Accumates seem to hold together much better than the first ones, IMHO. A kiss with a soldering iron on the seam of the box will usually solve the older "falling apart" problem.
How big a train are we talking about when Accumates fail? how many people run more than 12 car trains on their layouts? I run a mix of both Accumates and MT's. Haven't really had any issues. My trains range in the 10 car length, so no problems for me. To those of you who hate the Atlas truck mounted accumates. Send them my way. I could use about 20 pair of trucks to flesh out my fleet with MT style couplers.
Ed, To expand on Steve's response : Make sure the coupler box is snapped shut, then heat seal the box with a small soldering iron, or a T-pin heated over a candle. Heat sealing is exactly what Micro-Trains does with their factory assembled couplers, which is why you rarely hear about MT couplers exploding. It does, however, happen, usually to customer assembled MT couplers that were not heat sealed per MT's directions. DAMHIKT. BD