All kits have limitations. Stillen kits can be modified for more power but its limited on what you can get out of it. Intake design, intercooler it's all limited and can't be modified that much with out bolt on additions like Water/Meth injection.
As far as plug and drive the tune that comes with the kit is fine if your not looking to be competitive. Its a conservative tune, most guy's (myself included) will take it to a tuner and run it on a dyno to get the best results out of it with out blowing it all to hell!
Yes the Stillen Kit is reliable to a point. I recommend getting rid of the plastic idler pulleys and replacing them with aluminum version from auto zone. The plastic ones tend to fail. Also the kit comes with a cheap blow off valve made by Bosh. It to is made of plastic and I have herd of them not closing all the way, will effect your tune. Recommend a Turbo Smart 25mm BOV to replace it.
You do all that and change the fluids regularly and get a good tune that's not maxing your kit out and it will run for ever..
I bought the Stillen Kit, I am looking for HP gains but nothing to crazy also the kit is cheaper than most others.
GTM is another brand, there kit comes in stages. I & II and they just came out with a Twin SC system. They are a more flexible design and can be easily upgraded to more HP .
I always liked that Super Charged vehicles got good or better gas mileage when driven normal. Thats 98% of the time for me. Thats the reason I didn't go with turbo. Stillen was cheaper and I have freinds that have them and don't have any issues.
Well hope this might have helped some.
