I too have a Dawes Giro 400, I got mine on 1st Sept.
I'd been trying to commute to work over the summer but first try destroyed the bottom bracket on my old mountain bike and went through trials and tribulations trying to use my father's late 80's Peugeot drop bar. P*ncture city though I must take the blame with my tuffy type tape installation, having decided to drop the tape I immediately managed to bend the derailleur into the wheel and bend the mount as well. LBS advised They don't make them like that anymore so then tried the Father in Law's 1984 Dawes Lightning changed the tyres to the "that's an obsolete size these are the only ones". But they're a rounder cross section too wide for the guards and still rub the frame.
So I went for the Giro, I like the idea that it will take guards/rack and might want to try audaxing in the future. Shop changed the standard tyres for Schwalbe Billzard Sports for me and no fairy visits yet.
Since then I've done 437miles mostly my 11 mile each way commute. I find the ride a little harsh but that's down to the really bad road surface.
I've not lost much weight but I've had to drop a jean size. I am also finding the run/squash at lunch time perhaps a little bit too much as well currently. Hoping I can keep the momentum going into the bad weather.
Next it will be clipless - considering the SPD MTB route. The cycling bug has bitten