I would feel like a fool if I was to say how many 375s I have owned

In my opinion the 375 or 458 bore sizes, whether they be 375 H&H, 458 Win/458 Lott or the 378 and 460 Wbys are a better bet than any 416 and the reason is bullet availability. Look at the bullets that Hornady, Speer and Sierra make in 416....and you won't have much to look at.

Get into reloading and you can do things like 40 grains of 2205 (H4227 for our American friends) with 220 Hornady flat noses which does about 2100 from most 375s and will shoot inch groups from accurate 375s.

My feeling is that the 416 (or404) needs to be in a high end custom gun.

The 375 will give you all the "fun factor" and if you reload you can virtually toss out any other calibres you own.

Mike