I have always had all my CD's in iTunes as AIFF(same as WAV). I love lossless, and have been willing to make room on the hard drive for it.
Only as recently as two months ago, I finally bothered to test out ALAC. Sure, I read all the facts

yet was somehow unsure.
Apple Lossless sounds perfect, just as the science and the data said it does(go figure!). I converted all my AIFF to ALAC, and not only have I saved over 150GB of space(which is about $50 of my HDD's space/dollar ratio), but these files actually have built-in tags, so I will never have to re-enter the titles, artwork, or other info-data, again. When I lost my iTunes library three years ago, I had to redo the whole sha-bang. That sucked!
I would've loved if

allowed FLAC in iTunes, as it was already so popular

apple: had their reasons), but for iTunes....ALAC FTW.
PS if you rip your CD's in a lossy format, and someday, you have the space/need for a different format/bitrate, you will have to re-rip from the source. As you may already know, you cannot transcode lossy without it sounding worse. Lossless is your master source, and will serve you well.
PPS I only have MP3's on my iPod, however. I encode, transfer, and delete/backup the encodes. To keep me from doing this twice, I keep a full backup of my iPod's HDD with SuperDuper.