London to Edinburgh: ECML or WCML?

Do you prefer travelling from London to Edinburgh via the ECML (East Coast Main Line - LNER and Lumo) or via the WCML (West Coast Main Line - Avanti West Coast) - and why?

I ask because I went to Edinburgh last summer but I only went with LNER and lumo. I loved the ECML between Berwick-upon-Tweed and Dunbar with lots of amazing scenery, but I haven't done the WCML north of Stafford (well, I've done the WCML to Manchester but it's a branch off the mainline so doesn't really count) yet. I might be going to the Fringe Festival next summer and I hope to go with Avanti for a change just to experience the WCML north of Weaver Junction