Genesis Tarn 10 or On- One Whippet

I own the former - laid back, rigid, steel, semi fat tyres, heavy - use it quite a lot mostly for what you might call gravel rides - plenty of road, bridleways and easy paths - the occasional blast round Sherwood pines.

Thinking of selling it for the latter - for no other reason than weight (the bike not me).

Do you think it'd make a noticeable difference? I do like the Tarn - the position just seems to suit my dimensions - is it a case of the grass being greener ?
[Castle Donington Ladies FC - going up in '22]