Supposedly its easier to change the spark plugs with Hookers over the TES. I have to use a special telescoping spark plug socket with my TES headers.
There's a couple that are a little more work to get at but nothing crazy. Think the last couple times I've done it the headers have been off so it was really easy .
I don't see SBC parts being hard to find for a very long time, no worries here, no matter how many people jump on the LS bandwagon.