I notice some spey rods use snake guides and some use ringed guides.
Is there a rule of thumb for when to use snakes or rings?
Scott

Not really. Over time, single foot guides have become more popular, as improvements and variety occurred.

I build only fly rods, including Spey and use single foot exclusively unless the customer request snake. Most don't!

I'm pretty sure when Scott says "ringed" guides he means ceramics.
If I am correct and that is what you mean - there are two schools of thought.

Mine is that the lighter build is always best since they will not rob the blank of performance as \ringed (ceramic) guides will.
Especially true of light fly rods AND Spey rods that are, at best, floppy things anyway.

The other school of thought is not concerned with weight near the tip of the rod and is of the opinion that the "slickness" of the ceramics will reduce friction. Which is, IMHO, misguided.

But if you WERE talking about snakes or single footed guides - I had only used single footed guides until a couple of old timers convinced me to try the snakes because "they shoot line better".

After may fly rods with both - I am back to the single footed REC Recoil guides. But what I do now use are REC Recoil single foot spinning guides between the ceramic stripper and the last 5-6 single foot running guides. i.e. #16, @12, #10 then the runners #8's are too small. The spinning guides are very light and keep the line away from the blank.
Herb

Thanks Herb, that was what I was looking for, practical experience.
Scott