I have been pretty impressed with my Pax 2 for a few years. They have a ten-year warranty I think but they are built to last. I grind my herb pretty much to a powder in a coffee grinder and gently pack the oven. I usually get 13 to 16 good tasty rips off it before it gets weak on the vapor.
I bought my Da Buddha vaporizer in 2011 and it's still working like a charm. It's not a "carry-in-your-pocket" unit. It's really for home-use. I think it works great for flower, specifically.
That Da Buddha is similar to my SSV (Silver Surfer Vape). Both are made by 7th Floor Vapes in CO. It took a little figuring out at first to get the big rips I need, but now it's my favorite, and is almost the only way I smoke anymore. I was always a pipe or bong guy before I got a real convection vape.