There's really not many things in the price range that can compete with the R-50 in the first place, never mind keeping its strengths and improving on its weaknesses. At a stretch the ACS T15 might be an option but it's hard to justify its price over the RE-400.
Well, the R-50 isn't the brightest of the bunch. In fact, with deep-sealing tips and an impedance adapter it's one of the most neutral. So, if it's too bright, it might be safer to avoid the TWFKs all together. The one I could recommend (GR01 from VSonic) is not as durable as it could be if it used the VC02 housing/cable setup. Hopefully it will get updated. The AX7 is built better but it's not less bright than the R-50.
joker, you got the AX7?
Edited by Zelda - 3/17/13 at 1:03pm