The short answer is that which brand of sink tips you use matters less than almost anything else, or any of your other gear. So I’m with eriefisher, if you are happy don’t change because there is virtually nothing you can do brandwise that will make any difference. They are just sections of perfectly level or nearly level line with densities greater than water, and the only thing that matters is their weight/density, diameter and length.
Yes there are some significantly tapered heavier “tips” that are designed to be used mostly on more delicately tapered heads, and you could try them on your skagit head. But in my experience they don’t really change much about the already clunky skagit experience, and just lower your fly carrying capacity.
If you really want to understand how things work, and debug things when they go wrong then you really should buy a $10 grain scale (available on places like amazon) if you don’t already have one. Nothing and no product will help better than this cheap gadget. Plus it can help ID tips and lines when you have lost track.
The above said there are a few thingS that are important, all of which are simple physical attributes, not “brand secrets”:
1. Matching a tip to a head - the grains/foot, aka “linear density” of the tips should be less than the grains/foot of the tip of your line. Preferably similar, but less as you make the transition. This is why there is a carrying capacity - heavier line tips can carry heavier tips. The labels on commercial tips are usually very accurate for linear density, and this is easy to check with your grain scale and a tape measure. The Rio
T-stuff is even named according to the linear density with T-11 having a linear density of 11 grains/foot, and so on. Note the number does NOT refer to the sink rate directly, just the linear density.
2. Sink rates. Ugh! Sink rates depend only on the linear density (or alternately the total weight divided by the total length) and the diameter, and NOTHING else related to the tip. Yeah, the salinity/density of the water play a small role. Unfortunately here the labels of different companies DO vary wildly from company to company - and technically from reality as well. Apparently this has to do with the way the sink rates are determined and/or the rigor used in the process itself. From an engineering/physics point of view virtually EVERY company significantly overestimates the actual sink rates. As a quantitative person I suppose I should care, but I don’t. When I drive a stick shift I don’t worry about the precise gear ratios I just go up when I need to and down when I need to. Same with tips. But just something to remember when you switch brands - S8 from one company may not sink exactly the same as s8 from another.
There are exactly two minor issues with level sink tips I can think of that are brand-dependent.
1. What is the breaking strength of the core, is it what the companies says it is, and is it enough for the fish you are going after? Almost alway it is plenty, but occasionally even companies like Rio
get things wrong in the construction process at first when they introduce a new product. This happened with their new model sink tips a few years back but was rapidly discovered and fixed.
2. How easy is it to weld loops in the particular material. This is only important if you want to build your own.
But if you want to try new things I’d recommend trying out the (super old) Rio
replacement tips if you haven’t already. Probably similar to what was mentioned above. Again, they are just level sections of line that sink at different rates, but you can adjust the total weight/densities of the sets to match the line, AND the different sink rates have the SAME weight for a given set so if you find a sweet spot for a given line you will stay there when you switch tips. Very nice for more sophisticatedly tapered heads, but maybe not quite as relevant for a skagit head. But that is just my take so see for yourself. I still also use them on my lighter skagit heads 7wt on down.
The other thing you could play with are multidensity skagit heads rather than tips. The Airflo FIST head introduce several years back, for example, are super nice skagit heads and they really do ALTER the experience with tips, and are especially nice for places where there are not a ton of snags on the bottom.