At the time I was looking to change around my drive train I had a choice of going Mega or switching the crank. IRD was on Version I of their free wheel (not good). After chatting with the LBS and trying the mega on a friends walmart bike I started leaning towards cranks. 48-36-24

If IRD does not source in china I'll use them as my next replacement but 13-28 shimano are easy to find and at > 20 bucks a pop, new chain/freewheel as needed.

Note: I use 36x28 a lot and it's -easy- to find with friction shifters