In my Mk2 Octavia I had uprated speakers. DLS 6.5 components upfront and DLS coaxials in the rear.
Initially this was driven by an Alpine 9583 if I remember correctly. I hated it, couldn't make it sound right, so put the standard HU back.
Then came a MFD2 which was light years ahead and finally I ended up running those speakers from a RNS510 (Columbus in Skoda speak).
To my aging ears it sounded pretty good. In fact better than the current RNS510 and 10 speakers I have in the Golf.
For me I think the speakers need to be the first port of call as I am a fan of the RNS. If I can amp them then even better.