If you're looking for a cheap and decent ortho headphone, look no further. For certain music they will be far better than anything else in the price range, while for other types of music they might not be the best option. I've not used them myself, but I've researched them heavily and was considering buying them on several occasions.
Personally I'm using a Beyerdynamic DT150 (like a DT770 but much more refined and balanced despite its huge bass capability) driven out of an O2 amp with a Fiio E17 acting as DAC. I don't think I could bring myself to change - tempting as the Fostex may be, it will be a downgrade in so many areas that it might as well be a sidegrade overall.
Also keep an eye on
Audible Bond - there is a very trustworthy guy from the UK manufacturing modded Fostex (his model goes by the name DBV#3 T20RP), though he's on hiatus for a while.