I love the construction on these. It's been a while since I've seen quality welds on an exhaust manifold. Too many shops use machine tig or slather chrome all over their welds, making them look cheap. Fast Intentions really did a great job on these.
The stock driver's side manifold was a complete pain in the ***. Not only did we have to remove the steering linkage, a whole mess of hard coolant line and hoses were in the way. We had to raise and lift the car numerous times to figure out the best way to access the bolts.
After a few busted knuckles and tools, we finally managed to get both stock headers out. It took us about 4 hours to take them off, another 1.5 to get the F.I LTH on the car and bolted up. So about 4.5hrs total install time. I do regret not wrapping them though. Time to take them off again
Just kidding.
Sound wise, there's not a big difference between these and test pipes, however they do definitely make more power. There's a little more RASP, but nothing totally nasty sounding. I like a little bit of rasp in the exhaust note. Construction, as mentioned earlier, is top dollar. These look miles better than anything else offered on the market currently (Stillen, PPE, etc). Cost-wise, I'd be hard-pressed to pay full retail on headers given the gains aren't as large as most other bolt-ons, however I got these at a good price so I think my dollar was well spent.
Overall a 9/10 for build quality, construction, and power delivery.