I've mentioned them on a few occasions; I've been debating between that one and the K&N typhoon sort ram.
One thing is for sure, True Flow will not void the warranty, as it doesn't relocate or alter any emissions fittings. Hoses go to stock MAF housing, stock airbox is kept intact. the Filters they use are cell-foam style filter panels (not cotton gauze like TRD
or K&N) they will last longer, and flow better. Other foam filters that are popular are the HKS sports filters.
I'm keeping my tuning mild, since it's my daily driver, the True Flow Intakes
are quite streetable, and do help performance about as much as any short-ram Intake
out there, the bigger gains will come from a full-length CAI
Now, if they'd add in a Carbon Fiber airbox with a cold-air pickup, you could see some awesome gains.