ECUTune, for those of you that have/had it

[JLHollowX13]

im thinking about getting the stage 1 chip. i just want to know what it does. is it worth the money? are there any fallbacks to getting it? how much does it improve everything? will it still work if your ecu is throwing a code (mines throwing one for the speedo) or will it be over ridden? what kind of results wil i get performance wise? im not sure what else there would be to know, i just want some personal input from people that have had it. im on a tight budget and i could use that money to get some other things my car needs. i know the chip lets you run 87 octane and it changes the air to fuel ratio, but how much does that actually improve it? (the change in air to fuel ratio using higher octane as i probably would still stick with the higher grade stuff) i want some changes that i can feel and ill get a good amount of performance for the money. any info people can give me or opinions would be great help, im only asking about the stage 1 because the others seem like more than i need, i just dont see how they would benefit me because im not doing any heavy mods, just want a little more performance the easiest ways. thanks!