The cash alternative is a nice option so you can pick something Wheelies Direct does not stock. But it means you don’t get as much bike maybe!
My thoughts;
5 is a great bike but try one if you can, not to all tastes. My current bike, it’s a hoot but also love my mates Zesty.
Scott Genius 720. Bloke I work with just bought one (3 months) Took it to the lakes, had a go. Nice bike BUT he is already having problems with the remote system it uses to adjust the forks and shock. Its a nice idea but so was pop lock but sh*t in the cables and it just becomes more stuff to fix and maintain. That would by worry one this bike, not the wheel size.
Megga…mini downhill bike. Maybe too much for longer rides and if out are not in the Alps etc regularly might be a lot of bike to hump about, if it is your only bike.
No idea about the x-flow. Sounds like you like it tho.