I've had the opportunity to tie on both the Dyna King Excalibur and the Renzetti Master and wanted to provide my thoughts on the differences. I can't speak to other brands but hope this helps someone trying to do research on the flagship models of these two companies.
Small hooks (18 and smaller): Dyna King with midge jaws
- I find the angle of the jaws on the Dyna King offer more room to work with smaller hooks. The adjustment abilities on the jaws also provide me with access options that the Renzetti just doesn't have. Not to say the Renzetti is bad when it comes to working with smaller hooks but the Dyna King just makes the experience a little more pleasant. If I only had the normal Dyna King jaws then I'd have to give the advantage to Renzetti here.
Spinning Deer Hair: Dyna King with normal jaws
- The Dyna King is a tank of a vise. I have the pedestal version of both and I find the Dyna King offers more stability when I'm having to exert a lot of pressure on a hook.
Ease of jaw adjustment: Renzetti
- Adjusting the jaws on the Renzetti to accommodate different hook sizes is incredibly fast and easy. The Dyna King takes a little more fiddling to find the sweet spot for the jaw adjusment.
Hook range with a singe set of jaws: Renzetti
- I've tried everything from 6/0 down to a 24 and the Renzetti jaws can hold them all. I can achieve the same with my Dyna King but need to switch between normal and midge jaws. Yes, the normal Dyna King jaws will hold small hooks but the midge jaws make tying a lot more pleasant.
Size 8-10 hooks: Renzetti
- This requires a special mention because I've found this size range to be where the Dyna King jaws struggle the most. Yes, the Dyna King will hold these hooks but not without spending more time than it should to find the sweet spot on the jaw adjustment. In my mind this is really the only drawback of their jaw design.
Large hooks (1/0+): Draw (with bias towards Dyna King)
- I've experienced zero difference in the ability of the Renzetti to hold large hooks compared to the Dyna King. However, my personal preference is for the Dyna King for no other reason than it's a larger vise and I find it more comfortable to use on the really big stuff.
Material Clip: Renzetti
- The Renzetti's built-in material clip is fantastic. It easily flips out the way when not in use. It's one of those options that you don't realize how nice it is until you use it.
Angle adjustment options: Dyna-King
- The angles you can achieve on the Dyna King jaws are incredible. You can adjust the the jaws so you can almost tie a fly from almost any angle you desire. This offers some really fun methods for doing parachute posts and opens up a lot of options when photographing a fly.
Overall build quality: Draw
- Both are fantastic vises that are well built. Yes, both have a few plastic parts as well but this doesn't bother me.
I can see myself continuing to use both vises and it's hard for me to pick a clear favorite. I can see myself using the Dyna King for the big stuff, deer hair bugs, and the really small flies along with the times where I want the ability for maximum adjustment options. The Renzetti will come out for the rest as it's just a pleasure to use.