In terms of performance – Depends how good a rider you are. Most wont see a difference.
In terms of look – its up to you.
In terms of fit/comfort – its up to how well the bike is fitted to you.
Downhil – I ride a 6 year old Orange 5 and love it. I ride with a bloke who has a 5 Spot and he swears it descends better – he is a good rider and probably right. It is very sturdy and those extra linkages must count for something
Uphill/Flat – The 5 Spot will typically be a couple of pounds heavier. So the
Cost wise – I guess an extra grand at least.
I like the "englishness" of the Orange Five and like the thought of keepinig some honest english craftsman/engineering company in business.