Brand new.

if you hasn't test them out, do it, then choose the one that you find comfortable to ride with.

if you went for the Plug - change the tyres to a decent 23c one, you'll find it ride much lively and fast.

langster - remember the stock wheel are heavy, so bear that in mind if you think the langster is heavy, all it take is a change of wheels (not immediately of course) to a lighter one (not necessary expensive at all) will make a difference.

Paddy Wagon, no idea as I hasn't ridden them before.

Excellent, I shall pop in to my local CycleSurgery this week.