They are pretty easy to tune. Actually the majority of folks find one of the 10 map presets to be tuned just right for them. And for those that need a little adjustment, it's not hard to map and get it right.
To emphasize what Duster said, they're very easy. I have an FMF full exhaust with just an Outwears lid on my stock air box. The motor is stock except a Wiseco 12.4:1 piston. I race XC and usually set it on 5 or 6. Some guys I know go all the way up to 9.