Which is more future proof QNAP TVS-h1288X or TVS-h874?

[Enquiries]

Hello, I currently have a TS-451+ but want to expand to at least a 8 bay. I currently use my NAS for Plex and device backup but am looking to expand my Plex collection for 4k, continue with device backup but add surveliance for 8 cameras and a PCI slot for GFX card (to help with encoding). I was looking at the QNAP TVS-h1288X but was unsure if it is still as future proof considering its 2 years old and the TVS-h874 i5 version (unable to find i7 version here) seems very impressive.
With what I am looking to use it for, which is more future proof QNAP TVS-h1288X or TVS-h874?

Regards
Vince

[ed]

Yes, we were surprised about new 74 series performance. It is better than 88X series regarding things like Plex transcoding etc.
Technically 88X series us more powerful. But regarding media, definitely, 74 series is better. (even i5)

I hope this helps.