They are pretty easy to wire in, but only if you are used to wiring in in aftermarket ecu's in the first place really, can be a bit confusing the first one you ever do.

SMC is a good ecu but IIRC you'll need to alter your crank pulley to run it as im pretty sure it cant handle the standard crank trigger pattern, but to be honest its quite a few years since I last mapped one.

The early autronics are a bit limited on features in terms of you need to change the firmwear chips to activate different features so you cant have everything in use at once.

The newer SM4 units are much better in this respect than the SMC/SM2 and personally I feel are worth the extra money they cost.