Engine Performance chips

Has anyone out there used a chip from www.engineperformancechip.com?
What were the results like?
They offer a "Power Performance Chip X2" at $69.99 with a claims of
up to 50hp
improved torque
blah blah blah
I tow a travel trailer and need a little boost on some of the hills where we live (at 6300ft and above).
I realize that at this altitude my HP is probably down by 25 to 30 % anyway due to the thinner air (less O2). I'm struggling to figure out how I can get much of an increase in HP without having an O2 tank squirting into the intake!

I dunno man, 2 wire hookup and adjustable? It doesn't say what it hooks up to so I'm going to guess it is either the coolant temp sensor or the intake temp sensor which is a totally bogus way to call a rheostat a 'chip'. Not to mention the chip fits 90-08? Another bad sign. Also they sell an electric supercharger which would lead me to my final 2cents- I would not buy ANYTHING from those guys.