About 10 years ago I often travelled to Anglesey on business and preferred the A5; I only used the A55 a couple of times.
The choice is between a largly modernised (much of it M-way-like), fast and dreary road through the outer suburbs of Liverpool :lol: (the A55), and a slower old-style A road through some of the best scenery in Britain (the A5).
I usually travelled around March-April in the evenings, and on the A5 through Snowdonia I would often go for miles without seeing another car (even during the day); just me and a gently snaking line of cats-eyes shining ahead. They were some of the most enjoyable drives I've ever had. I had no caravan, but one would be no trouble.
Returning home at leisure I would often take roads right througn the mountains on unclassified and gated roads, via Bala and Lake Vyrnwy - but that's definitely not for a caravan!