Interesting points brought up here. Myself, I do worm my pigs. Personally I feel comfortable doing so as it is a very small dose given only four times per year. When I had experience of pigs with unexplained weight loss which was corrected with the use of Panacur, I decided to routinely treat my own pigs. My decision was as a result of my own experiences as well as research into both the "pros and cons" of worming. People will come to different views on this unless perhaps there is a scientific study of some sort which proves, one way or the other, the safety and effectiveness of using Ivomec and Panacur routinely in guinea pigs.
Of course, it goes without saying that forum advice does not replace veterinary advice. Even though it goes without saying, it is always said. The big problem is that most people who post on here do so because there vet is quite clearly useless with guinea pigs, and many vets have given up entirely on the pigs. A number of vets have listened to the ideas the owner has as a result of advice sought on this forum, and in some cases, the owners own research has actually saved their guinea pig. The importance of having a reliable, experienced vet cannot be emphasised enough, but for those who cannot find a good vet (but are lucky enough to have a vet who will listen to the owner), the advice given here can turn out to be very important.
I agree that another difficulty is keeping up with new treatments evolving, and keeping up to date with all developments in the field. However, I do feel that unless there is a probem with previous, "old-fashioned" treatments, there is little reason to rule them out, especially since most vets also rely on such older methods - and such treatments have served many guineas well over the years.
A good example is the antibiotic Zithromax - a few people here have had fantastic results with the use of Zithromax on guinea pigs, but how many vets would even consider using it on guinea pigs? Thus we go on emphasising the doses for Baytril and the like because that is what most vets use, they have not caught up. It is a widespread problem, unfortunately, and until there are some frequent training sessions or something similar to keep vets up to date with the latest treatments and techniques, the large majority of vets will remain some way behind the few that are leading the way.