I have stayed at the Pyramida several times and, although it is approximately 1.5 km west of the castle and 3km west of the Charles Bridge, I have found it very comfortable and always reasonable. Modern without the charm of downtown though.
Did a quick search for the end of September and came in with a low rate for 4 week nights at about 69 Euro/night. Not bad for a 4 star but you will have to go to the internet room off the lobby bar for access as they have no wireless.
We did have our car when there but public transport is just outside the door. Try the following info:
http://www.hotelpyramida.cz/pyramida...x?content=uvod
As for the local pubs...I don't think I've been to a bad one!
Cheers