supose you have a mp3 file..
converting an mp3 to a flac wont make it better quality..
but when someone has an original recording of a show.. people like it to be uploaded to flacs because that is the best quality.
honestly, it doenst really matter that much... if you want something that is almost as good as flac but takes up 10 times less room.. then wehn you download a flac, convert it to mp3.
If you are planning on having a lot of bootlegs in flac, you should get an external hardrive because otehrwise your disk space will dissapear very quickly.
If you want a good program that converts files from flac to mp3s and wavs then go to download.com and search for dB power amp.
thats what i use, help alot.