Yeah, some of those welds look marginal but I prefer mandrel-bent tubing which most muffler shops can't fabricate because of the cost of mandrel bending equipment. Compression bends that the fabricator obviously used to make that exhaust significantly reduced the diameter of the pipe, slowing down the exhaust gas velocity, reducing HP and torque because of increased back pressure and turbulence, and also increasing heat. If that's 3" tubing, each of those compression bends has likely reduced the inner diameter to around 2 1/2" or even less. You want to eliminate back pressure while maintaining exhaust gas velocity. Even though the rest of the exhaust is 3", those compression bends essentially make the entire system 2 1/2", as they act like orifices.
95nblown is happy with his exhaust, so drive on. It is not my intent to throw shade on his particular exhaust, but rather point out the general issue of mandrel-bent vs. compression-bent exhaust piping.