I use a variety of MP3's mainly 160-320kps depending on who good the original source is. To be honest you only notice how good the Shuffle is with the right source material. Some types of classical and acoustic stuff I reckon sounds particuarly good on it.
There was a thread about 5G vs Shuffle a while back, I think it was more or less split. On one hand the 5G is new toy syndrome, on other hand many people who say Shuffle is great don't own one, it balances out I think.
I just got a shuffle the other day and I have to say, overall I'm impressed. It definitely sounds better than any flash DAP i've ever heard before and it seems very loud for its size. The sound is virtually the same as the X5, with a tiny bit more punch to the bass. The ER6i definitely sounded better on the shuffle, whereas I prefered the X5 when using UE Super.fi 5 Pros where I felt the mid-bass hump was less exaggerated and the mids a little less fatiguing (though this is just personal taste).
My only gripe with the sound was that when using the Super.fi 5 Pro the shuffle output had noticeable amount of noise that increased as the volume was turned up. Not a huge issue, though with some older acoustic stuff, it was kinda annoying.
I also found that when playing high-bitrate VBR mp3s, I would occasionally hear very short "blip" sounds. My mp3s are fine and the sound artifacts seem to occur randomly, though infrequent enough for them to go unoticed.
I also didn't like the fact that you had to install something as bloated as itunes+quicktime for a simple flash player. It loads up an extra three processes at startup and when I tried to disable these, my computer would suddenly reboot when transferring music. I'm still not sure if this was the real cause, but I said enough is enough and uninstalled itunes and now simply use iPod shuffle Database Builder, which as close to UMS as you're gonna get.
What impressed me most though is how convenient and well designed the whole package is. The player itself is just perfectly designed for its intended use, it just lets you play music without bothering you in anyway. I give it 8/10.
I use MediaMonkey with the Shuffle. I also had a problem with VBR's so I just use CBR's. I like it because it just so simple. The only problem I've had without iTunes is that the tracks I transfer aren't volume leveled. The option isn't working for me in MediaMonkey. I've not a had a chance to resolve that yet.
i'll join in and also say i was impressed with the shuffle's SQ when i got it a year or so ago. what really keeps me coming back, though, is the simpleness and elegance of it. just throw it in your pocket and go... nothing more, nothing less. you can get around having no screen by carefully laying out playlists in advance. i have a 1st gen 5 gig ipod that i can barely use now after being spoiled by the shuffle's size. i really hope apple doesn't decide to drop it from their lineup because i'm sure the nano is stealing many sales from it these days. it still has it's place in their lineup IMO, but that may not mean much for the bottom line.
If I purchse a Shuffle, what options do I have if I do not want to install iTunes and am using a Windows machine? I am willing to listen to formats other than Apple's (e.g. WAV or MP3). It appears that the Database Builder mentioned above is no longer supported in Windows native format. Do I have any other options available to me?