score:10
You will find less traffic on Manali route because majority of commercial and defense vehicles use Srinagar route which is also a better quality road. Srinagar - Leh route has a lot more options as compared to Manali - Leh route for both accommodation and places to eat. Manali route does not have as many petrol pumps as Srinagar route does. If you do go via Manali, the only large town (not so large) is Keylong and that is the only place in addition to Sarchu where you can find decent accommodation. Srinagar route has plenty of places to stay.