Part of the problem, as I see it, is finding a dealer network that is good all accross Canada.

Quebecor World went national accounts Yale about 2 years ago. They ran into huge problems here in Alberta because the dealer (AR Williams) doesn't really want/like Yale and basically refused to service them.
(to be fair they didn't actually refuse, they would just take 10 weeks to repair a burnt traction motor post)

Going to national accounts, makes it very difficult to get around a bad local dealer. In the end, a compromise was struck and Edmonton gets serviced by the Hyster dealer.
BUT, all new equipment must be Yale so they are still stuck for 3 more years...

Rona, has forced all it's branches to switch to Shyster, which means they must deal with Wajax. We recieved some resistance from a few locations. This led to our PSR's having to get Rona big wig's to put pressure on the culprits.

Also, be aware that if you are going to tie into a particular brand, make sure that brand has all the different types of equipment available that you might need in the future.
(ie. if you tie in with Raymond, you'll need a different supplier for IC trucks etc.)