I'm not sure about CR2 Editor and why it doesn't handle large files well. I always use CR2 Builder and have never had any problems. I love CR2 Builder because it allows me to open up two files at once. One on the left and one on the right, so I can compare or even copy from one to the other, it has many nice features that I like and some I haven't even used.

Here is a direct link to the file and, if the direct link doesn't work, I'll list the page where you can get it (it is also in FREE STUFF here at Rendo)

CR2 Builder (Direct Download Link)

CR2 Builder (Link Page)

The page link will ask you to install  language set, you can just cancel it (Unless you read Japanese and want it hehe)