Exhaust shop vs. Exhaust systems

Any real difference between the exhaust systems (Cat-back in my case) that are pre-made ie SWorks, Corsa, Magnaflow,etc...) and going to a local shop who will bend the pipe onsite and add a muffler ?
(Performance, price, quality)

Thanks

Short answer is no. If you have a good quality "muffler shop" that has experience building exhaust systems, has a quality bender and uses quality hangers then you will get a quality exhaust. Big difference is the "exhaust systems" generally have a lot of R&R into the mufflers they make and match it with the exhaust pipes. An exhaust shop is going to put the muffler you want on and bend the pipes to exit where you want, so it may be difficult to replicate a particular "exhaust system" sound if that's what your looking for. As far as performance gains, they are minimal with a cat back. As far as price, depends on the muffler shop but generally it's cheaper (at least around my neck of the woods).

Quality bender is the key. Mandrel bent over pressure bent is why I'd go aftermarket first, unless you know a skilled shop with a good bender

One common difference between "muffler shops" and exhaust systems is that most of the systems mentioned here are made from 300 series stainless. Most "muffler shops" use aluminized steel, which will rust over time. One things to consider.

There's some good questions there for me to ask local shop.

Thanks !!