disclaimer: I am personal friends of the owner and the manager of IBI.
I shot the very first IBI barrel to be rifled and fitted to a rifle. It shot excellent.
As they went through production growing pains the performance varied, but after some learning and the introduction of the Suunen CNC hone their barrels are second to none currently available, and I have burnt out over a half-dozen Mike Rock (pre-Rock Creek), lots of Kriegers, and a few Benchmarks including a 308 that died in under 2500 rounds so I have a bit of a baseline to compare to.
I am not one of the 'buy Canadian' cheerleaders, and I shot Kriegers and Benchmarks in National level PRS matches while they were developing their product, but the last two IBI barrels, a 6.5 creed and a 6mm creed have both proven the equal to anything I've owned.
The 6.5 I shot last year is probably the most forgiving barrel I've owned. I'm pretty sure I could scrounge a 6.5 creed cartridge off a dozen different guys and shoot a 1 moa group with twelve different loads. It shoots anything and well and to the same poi. The 6mm creed barrel they just screwed on shoots 0.3 moa with just a jump test and 10 round velocity ladder test (aka the satterlee load development).
I have no experience with their prefits and personally would avoid them on principle, but as far as barrel performance, buy with confidence.