To my knowledge all new travelers I have seen has a double adjustment. The adjustment screw is only adjusted when you need to tie a very large hook from having a very small one and vice versa. Yes you do adjust the screw from time to time. However it only takes a second and not a problem. Most guys are tying dozens of each pattern or at least size range. After tying 10,000 - ?? flys jigs I never had a problem with hook slippage. Vices such as the regal style are great work horses also. However when tying many flys - jigs compressing the cam ( hooking lock)can be somewhat of a chore for some. Also when you rotate the vice over the cam lever is in the way.IMO. However we all get used to our tools and I am sure I could also get used to peaks and or regals. However I never heard of anyone complain about a renzetti loosing and I know a dozen commercial tiers that use them.