OOPS !! I stand corrected, other offices do have 5% and 5% so your predicament, on which one to go for ,will depend on the total premiums paid over the term.
I remember doing this exercise for a client a while back and Caledonian worked out the best on his details.
F. Kruger is right - you need to get quotes from all companies and establish which ones assume 5% increases on premium and cover and which assume cover increases at 5% but premium at a higher rate. A spreadsheet will then help you figure out which ones are dearer in the long run.