The narrow winged Plus 4 provides the nimbleness of the 4/4 with the performance of a Plus 4. It's better than the sum of the parts, and a real Gem.
I've not driven one, but that combination of good power and agility is what I've been developing with my 4/4 for the last 15 years. I used to think about 130bhp would be ideal, now I've got something over 160 I think that's about right for the tyres.