I went with the company LITORAL from la paz to lima. I booked a bus CAMA with 4 meals included. 28h (turned out to be 32h…) the price was steep, but the only company leaving that day la paz-lima.
Left la paz, everything fine. Boardercrossing all fine.
shortly after the peruvian boarder I had to leave the bus and change to another bus. The guy from the bus gave me a ticket and then ran away. When I entered the next bus and looked at the ticket I realised that I was scamed! It was a very basic bus (no bus cama single seat) the ticket was for one third of the price I payed in la paz (Good business for the busguy from litoral)
30h to follow with- of course – no food and drinks or rest
Avoid at any costs litoral!!!
My advice if you need to do such a long trip: go until puno and then book another ticket there. Plenty of busses and cheaper option.