since this has been bumped, might as well post something useful since a thread like this can help out newbies a bunch
Canned tuners
BulleyDog
Hypertech
ect.
Feats.
basic features, rev limiter changers, speed limiter changers, timing advancements(only on some tuners, not all include them), better AFRs
Pros.
cheap, easy to install, and idiot proof
Cons.
ONLY WORKS ON STOCK CARS OR CARS WITH MODS LISTED IN THEIR TUNES!!!!!!
someone on the G37 forums has tested this with hypertech at least but on his car with an intake, he lost 30whp, someone else on the MS3 forums also lost power when he tried using their tune with his ported stock turbo(although stock he did gain 10whp, 15wtq)
no custom tuning so nothing is specific to your car and its location
NO FI
Now for the real tuning options
Uprev
Ecutek
basically both of those tuning solutions have the same features, they can do the same things(Ecutek can NOT hold multiple maps
afaik), Uprev has been around longer than Ecutek
Pros.
true custom tuning
all the features Canned tuners have
ability to run different fuels
FI Tuning
Cons
Price
you need a professional to properly tune your vehicle