For me it's been great. When I finally found RAM and an SSD that was supported(!!), the experience got rock steady. On a headless Ubuntu server I'm hosting Home Assistant, Plex (the hardware transcoding and tone mapping is fantastic on a 12th gen Intel CPU), have tested out some "arrs" and I can tell there's plenty of headroom for more applications. The only thing is the fan noise when it really gets going. But I gather the 13th gen NUCs are much quieter. Considering a chassis swap in future.

But the tradeoff for a small NUC is a big power brick.