Are there other USB oscilloscope you'd recommend? Owon? Hantek?
Certainly the Owon over the Hantek, no contest (~ $100 for the galvanically isolated one), better H/W and performance, decent triggering. That's rather under your budget though (which is important at this level) - you're in that 'awkward' range between low cost USB and Desktops, with a bunch of so-so handhelds.
Pico might well be the way to go for you, they certainly have it quality-wise. They do decent oversampling which effectively gets you a couple of extra bits of vertical resolution, which might be useful for audio. Go and download their S/W, I'm pretty sure it will have an evaluation mode. Get the feel of their UI, it's certainly comprehensive but you'll probably either love it or hate it - it's quite 'windows app' in feel. Their support is first rate too.
If you really want to go lower cost with the Owon, it is still decent quality but lacks things like serial decode and a lot of of the fancy Pico measurements (it has the basic set). You can download the S/W too - no demo mode, so you won't get traces, but you can roughly get a feel for the UI. It doesn't need much of a laptop either.
I really have no experience of the Handhelds in that price range, you need to do your homework very closely on those.