I post a thread here on the use of generic viagra from Oz Meds.
Quality is the same, and the shit is potent I ended up moving down to 1/8th of a tablet when I bothered to use it. Even that small dosage made me rock hard and I felt like I had rock hard boners for a few days after.
When I was in Thailand I tried "kamagra gel" as an American mate who was punting with me wanted to try it, that shit was crazy I think I fucked 5 WLs that night.
Honestly I would say go ahead an try the generic stuff it wont be bad, if you are paranoid then go get a legit prescription from a doc here, without knowing your situation I would also recommend starting with a low dosage.
I sold most of the stuff I bought as 100 pill was too many, I think I have like 4 left as I never use it. This is completely anecdotal but I think a side effect of using it for a month is that my erections now are harder then before I ever tried it.