These are known for being welded in a way that they crack. The stainless ones had less occurances of the cracking issue, however they did crack as well. To my knowledge ZZP has not addressed the cracking issue or made any plans to fix it.
A few welders that have commented on the design etc, mentioned that the issue was in how the weld was being made and being ground down IIRC. They also mentioned it would be an easy process change/fix.
For the cost of a new Plog, you may want to consider a set of Speed Daddy headers, commonly found for a little over $200 with shipping. These are SLP knockoffs and are overall a great set of headers with an unbeatable price. Add in some torca band clamps from Frozen Boost and it'* tough to have an issue with them. W body guys need to modify their tunnel/firewall lightly to make the O2 sensors fit in some cases, however in an H body, there is likely more than enough room without modifying the car.
00 Regal GS: All kinds of cool stuff.