I have probably put in 50 of them. They are a little pricey but I feel they are worth the money. They give you the option of using dual or single fire (different coil used for dual or single) and I like the multi-fire mode. On big-bores and rebuilds we set the rev limiter and have the customer come back after the break-in period and re-program it.
The instructions are very clear and detailed and with a reasonable amount of mechanical ability, is something the do it yourselfer shouldn't have any problems installing. Remember to get on the proper engine stroke when doing the static timing.