Bigger is better. However, most people when considering their first saw are intimidated by a big blade wizzing around, for some reason it 'seems' more dangerous than a smaller blade. You don't have to put a big blade in a big saw, there are limits as to how small you can go, but it allows you to use for instance a small panel cutting blade (cheaper than its equivalent big brother with no disadvantage) where you only normally need circa 2" maximum projecting.
There is little IMO to be gained for getting a saw with a blade size larger than 450, and I have selected a 400 for my own saw that will cut almost 5 1/2". I would have been just as happy with a 450 blade size.
There are new regulations (a few years back) I believe for saws with blades over 12" which killed off the Sedgwick TA400 and required a redesign of their 450. The blade crown guard must cover the entire blade even when tilted and this can only I understand be achieved with an overhead crown guard rather then a guard fixed to the riving knife.
The extra HP and mass make for a far better saw that can do more. So, I can't think of a downside if you can fit one in in Go for it