Depends on the NAS used.
I've just had a drive crash (probably my own fault - and only about £45 to replace) but it's a concern. I've tried some NAS devices in the past, but hopefully things have improved now. I had a couple of Buffalo units. The first one wasn't great, but I bought another. One was supposed to be capable of backing the other up, but in fact both then crashed. I think I can recover one of them, but haven't had time to bother. The other was replaced, and somewhere I've got a new one in a box.
I agree about ripping being a pain, and it's not a great idea to rip loads of stuff, then have a drive crash.
I'm trying to get all my music rips onto drives in some form of order, so that I can simply copy drives when/if I need to. In the worst case I've still got the CDs and DVDs, but don't want to have to do that again if I can avoid it.
I tried using an Apple Mac with Time Machine, but in fact it was the TM drive which I screwed up. Moral - don't use a portable drive with a laptop.
I've just ordered a larger desk top drive, and I won't connect to the computers unless both the drive and the computer are on a solid base. In the future, I'll probably move to SSD drives, but I'd like the price to come down. I did make a couple of small SSD based USB external units by buying standard SSDs and putting them into USB caddies, and they are obviously more robust than hard drives if they are likely to be moved around.
For small scale work, I just bought this Toshiba gadget, which works with USB drives and also USB memory sticks -
http://www.toshiba.co.uk/hard-drives...eless-adapter/ It was cheap - under £12, but has taken quite a while to figure out, and I've not finished yet. It works quite well with an iOS device, such as an iPad Pro - but you'd need to figure out a decent player to run on such an iOS tablet. For hi-res sources, an App, such as PlayerXtreme might be needed - and of course some method of getting the output to a decent DAC.
Apart from the NAS or storage issues, how are people playing their music? Streaming, or downloading, then playing back from a dedicated music machine? Some might be using new models of streamers, and perhaps so-called hi-res downloads.
I tend to use Apple Macs but so far haven't gone for anything above 48 kHz 24 bits as source material - apart from one or two test experiments. The requirements become tougher if the best is to be obtained from (say) 192 kHz 24 bits, or DSD rips - and ethernet LANs aren't always very helpful - though they do seem to be getting better these days. In fact I've almost gone full circle, and I do now play CDs more frequently than I did a few years ago, when I had a major effort to rip 1000s of CDs.