Variety is the spice of life...
So if I understand your question, you have a Kimber CDP Ultra (3 inch) and are debating a 4 inch Kimber Pro or a Glock 36? You like the Kimber Ultra very much for carry.
I would say that the Glock 36 is very similar in function to the Kimber Ultra you already own and like. I wouldn't see much advantage or variety in buying a slim, short barrel Glock .45 when you have that base already covered with your Kimber. I would think you'd want something noticeably different.
The 4 inch Kimber Pro will be slightly different in feel than your Ultra - more grip to hold and one more round of ammo, combined with an extra inch of barrel and more sighting radius and muzzle velocity. Of course it will not conceal quite as easily.
One could argue that you should consider an all steel 1911 range gun with 5 inch barrel. Since you seem to want a .45, the 38 ounce steel gun will give you an easier gun to shoot well than the 3 inch, 25 ounce ultra. And it would be useful for home defense as well. If you want variety, the 5 incher will be much different than your Ultra - more difference than a 4 inch Kimber Pro.
Or if you really want a different .45, how about a polymer USP 45? It shoots very well at the range, holds 12+1 rounds and is reliable and very useful for home defense. It won't carry too easily, but you have that base covered with you Ultra.