The big con with a flat tappet cam is, if your break-in procedure wasn't done perfectly, and/or you are not using the correct oil (which is getting harder to find locally anymore), you run the risk of some lobes going round, and really messing up your crank, bearings and piston skirts. It happened to me, and many, many others. I switched to a solid roller, and never had an issue.
To the people that want proof that a roller cam makes more power than a flat tappet cam, give me a break. It's been proven so many times, its not worthy of a response.
