"So what is the general consensus on reliability on the GTM kits?" ...
or an other FI kit from Stillen or GReddy for example.
Several factors are involved with providing reliability with any of the FI kits:- The cash outlay for the proper FI kit itself for your goals
- The skills to self install or the cash for a competent shop to install
- The cash outlay for the supporting options (cooling, clutch, tune, etc)
- Probably most important is a proper tune after everything is installed
- A higher level of commitment to maintenance of the vehicle and the FI infrastructure
Do a lot of research before picking a kit to meet your performance goals. Also, be prepared for expenses beyond the FI kit, the installation, and a tune. Last, be prepared to be more involved in maintaining your ride after the initial install.