Favourite London - Cheltenham roundtrip

I never did this exact trip, but these are some favourite roads in that general direction.

(the detour into Blackbird is in honour of my old motorbike school)

PS: if somebody knows a nicer way out of London westways, please let me know. I always take the A40 just to get out quickly and take the M4 in, because of the additional bus/bike land to avoid the traffic.

http://maps.google.co.uk/maps?f=d&hl=de&saddr=paddington+station,+london&daddr=wooburn+to%3Acadmore+end+to%3Atetsworth,+ox9+to%3AOX4+6ll+to%3Agrenoble+road,+oxford+to%3Afarmoor,+oxford+to%3AMinster+Lovell,+witney+to%3Aswinbrook+to%3Atannery+close,+burford+to%3Amiddle+road,+burford+to%3ABourton-on-the-Water,+Cheltenham+to%3Aandoversford,+cheltenham+to%3Acolesbourne,+cheltenham+to%3Abaunton,+cirencester+to%3Abibury,+cirencester+to%3Acarterton,+ox18+to%3Aaston,+ox18+to%3Aabingdon+to%3Astadhampton,+ox4+to%3Awatlington,+ox49+to%3Atwyford,+reading+to%3Apaley+street,+sl6+to%3Awindsor+to%3Abuckhurst+road,+sl5+to%3Astaines+to%3Alongford,+heathrow+to%3A+paddington+station,+london&sll=51.404346,-0.77179&sspn=0.784729,1.845703&ie=UTF8&ll=51.650407,-1.087646&spn=0.780499,1.845703&z=9&om=1