That depends. With any "mail order" tune with a near stock car, you will gain about 7 - 15 rwhp. However, there are other benefits which include:
1 - If you change your gears, you can calibrate your speedo
2 - If you have an auto, you can change shift points and firmness
3 - Mods like plenums and TB can make car idle rough....programmer typically fix this issue.
4 - Some programmers (not sure about tthe hypertech) can read codes and clear them.
So, if you add all these things up, it is most likely worth it....at least it is to many of us.
If you plan of modding your car more, go with a unit that can take a custom tune which can grow as your car changes. Look into SCT. That is what I use and recomend. Visit their website and/or go to
www.modulardepot.com. There is a ton of info and users there. Get the SCT programmer and not the chip if you do.