I have three the 45 , the 60 and the small one ( can not remember the mm, but is is not the micro small). I tend to use the 60 the majority of the time. If I had to give one up it would be the 45 , and I would keep the 60 and the small one. ( the small is nice for curves). Yes the blades are more costly , but it lasts longer.
The 45mm has been around longer than the 60mm, so I think alot have just gotten used the 45.