The bike is going in next week to get the new suspension fitted. It really needed new tyres so I figured I would do the 21" front wheel at the same time. It will certainly ride different when I pick her up. 

Well I reckon you will be pretty happy mate, chalk and cheese to stock.

Update time, as expected the bike is a lot different to ride now. The 21" front wheel definitely tips in better than the standard 16". The rear suspension had to be made a bit higher to compensate for the 21. This has given me far greater ground clearance. The bike almost sits level now. It feels so much more stable and planted now, no more wallowing and scraping in the corners. The front Progressive cartridges do give a firmer ride but the stability is worth it. The rear YSS shocks handle all the bumps with ease. The bike feels much lighter as well once on the move. Really like my tyre choice as well, very confidence inspiring.