You're over thinking a very simple thing:
They are a good price
They are convenient to buy
The quality is good enough
This makes them good value.
So, buy them. Or buy something else. It's not rocket science.
What it is Nick, I want to install the Powerflex Bushes. I've read so many horror stories about the extra stresses caused by them that has led to cracking or even breaking the welds on the wishbones. A lot of the info that I have read suggests using the original wishbones to avoid this.
Those reports apply to attempts to replace the
rear bush with a more durable part. The problem is not the amount of weld or quality of the metal, but that all the experiments transfer the movement from the bush to a part that can only accommodate it by flexing. The welded mild steel sheet wishbone isn't designed to do that, and will always break if you apply a lot of force often enough. And a 1700kg car does that easily.
Fitting poly front bushes doesn't alter the design, as the movement is still around the bush's central sleeve. The difference is that the parts aren't bonded together and they don't have the oil-filled cavity, so they take a lot longer to wear out. So much longer that you can expect them to last the life of the car.