Spark Neo is really the best musical purchase I've made for ages.
While there's nothing very magical about them, the manufacturer waxing poetic about the "AI features" almost made me want to skip buying them, and I can't really talk about the quality of the guitar amp sims as I use the headphones solely with bass... it's just so convenient and fast to plug in the transmitter to my bass, turn the headphones on, pick a practise drum track from my phone and start jamming / practising anywhere in the house right away. No need for extra setup time, no cables dangling around, not tethered to a single spot.
It also helps that the tone I get out of these is very good for what they're meant for, and the instrument latency is imperceptible for me. I don't know if I'd use the Sparks as my first pair of casual listening BT headphones (they do work for that as well), but there's a very nice punch, energy and connection in the sound that makes my head nod while practising fingerstyle lines on top of funky drum loops - and that's a thing that's lacking from a lot of small practice combos I've owned.
Any nitpicks, then? Well, the headphones themselves are not the most comfortable for my head - but luckily they aren't awful at all either, just the "tight and sweaty" thing you get from a lot of sealed cans. Build quality feels fine in all respects, but not spectacular. I don't expect them to fall apart in my hands, and they feel fine for moderate practise periods -that's way enough for me for this price range and with such a brilliant utility.