An HP Tuner is way more versatile, but not the sort of thing a novice should play around with. A professional tuner using an HP Tuner would be your best bang for the buck, provided that you have the mods to justify a good tune. Diablosport is decent and easy to use for the average person, but very limited on tuning potential. These handhelds are known as "canned tunes" because they have preset tunes based on what are the most common bolt ons. Hope this helps.
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