You can get them with faster CPUs and Radeon graphics (e.g.
nuc8i7hnk) - but expect to pay closer to £700 for that, plus whatever SSD/RAM you configure/buy.
That comes with an
i7-8705G which is a 4-core/8-thread CPU. All things being equal, it will probably
not outperform the mini's
i7-8700B. Graphics is another matter and likely that NUC will hand the mini's ass on a platter.
I bought a refurbished mini last month (i7-8700B/16GB/512GB) and upgraded the RAM to 64GB. I also have a NUC7 (
NUC7i7BNH) and I used the 16GB memory from the mini to upgrade from 8GB (so now i7-7567U/16GB/512GB).
It's 6-cores vs. 2-cores, but if I'm just browsing Macrumors there's not much of a difference. But when running Office on the web (Word/Excel/PPT), I do notice lags here and there, and if I'm running Lightroom, the mini is the clear winner.
But holy crap the NUC is LOUD. Even when idle the fan is definitely present and audible while the mini is very quiet. When the CPU is pegged at > 60%, the NUC sounds like a small jet taking off right next to me.
With that being said, however, the NUC is cheaper, but it's also missing things like 4x TB3, which for some people will make adding eGPU and TB3 docks a better/flexible option since they won't have to share the same TB3 controller and give each the full bandwidth.