Just got the A35 in the mail on monday. had the A15 before this and was thoroughly disappointed especially when compared to the cowon plenue D. IMHO sony has hit a homerun with the A30 series especially at this price point.
For those who ask for comparisons between the cowon plenue D and the A30, i would say that it really depends on the type of IEM that you're pairing the player with. I think the sony excels more with dynamic driver based IEMs, or hybrids. the plenue D sounds fantastic when used with my BA-based customs, but when it comes to the dynamic/hybrid ones, it falls short somehow. Cowon seems to have a bigger overall sound stage but the Sony sounds more natural. Bigger does not always equal better in my books.
A much earlier review compared both players on flat, with no EQs applied. Cowon used to have the edge when it came to EQing, especially with mach3bass and BBE. Sony has gone back to basics by removing the clearbass option it used to have. you now have an additional EQ band to tweak when it comes to sub-bass(60hz). EQ allows for +/- 10 levels, although i'm not sure if this is in decibels. adjustments are VERY noticeable. There are a few other EQ settings you can play with but I've found that I needed to play with the EQ bands and DC phase lineariser to get the sound I like.
DC Phase lineariser is supposed to make your bass sound more its from an analog amp. not sure quite how it works but I like it lol.
User interface is extremely intuitive. you can access almost any setting you need by a few up/down/left/right swipes when in now playing mode. I didnt need a user menu to get myself started or used to the player.