Can't speak for the person who listed it but yea a lot of people don't like them because they see them as unnecessary and just an accessory that generally has no use. Don't really know of other problems with them personally. Anyway I know a few people that have used them over the years to fix the issue with pins walking. I'd give it a try before I had a machinist either open up the holes(I agree with not using a reamer from whoever said he was a machinist).
I've seen people use steel bushings after opening the holes to install them as well. I've only seen this done on registered full auto receivers though. It could be done on a normal lower but I'm assuming that the cost would make it more reasonable to just replace the lower.
I'd try the kns pins or something like them. I've seen a few extended pins with c clips on the end to prevent walking from the receiver(these have been around a while). I've also seen them with screws on the end. I'd go with the kns pins myself.

