I bought mine last July. I came with a 38mm motor mount. I called LOC and they said that they are changing it to 38. The old LOC catalog still says 29, but the new order form now says 38. I might fly mine on an H123W or an H148R, I have not decided yet. You can still fly 29mm motors, however, using LOC's 38 to 29mm motor mount adapter, MMA-2.
Mine also came with a 38mm mount. I bought the 29mm adapter for it for $3.00. I have since flown it on a I195 and it was off the pad before I knew what happened. I recovered it with no problems a few hundred yards away with no wind.