I am planing to buy my first dedicated DAP and i am between the A45 and Cowon Plenue D. What i want mostly in a DAP, is:
1. Long battery life.
2. Lots of storage/expandable storage.
3. Attractive, easy to use UI & good and easy to use physical design.
4. Sound quality.
5. Easy to transfer music with a Mac (preferably drag-and-drop method).
6. No additional apps, features, whatever. This will be used purely to play music files (MP3 and FLAC).
Based on everything i have read, A45 easily wins on point 3, but Cowon is a winner in points 1 and 4, while both are same-ish on point 2.
Still undecided though...
Find something newer, especially, if you have a big collection of files.
They are fine as a player, but Cowon, if I good remember, format SD cards only in FAT32, which has boundaries in number of files and depth of folders, but Sony has stupid on-any-start-building-database function, so it is unusable (sometimes it finished in 2-30 min and it is unusable during that period) or finished in bootloop (bc. sometimes it finished building not).