I carry a 642-1. I carry 2 Safariland Comp I speedloaders in JOX speedloader pouches on my belt.

My reasoning:

1) While it is highly unlikely I would need to shoot my gun in self defense, let alone need a reload, if I am forced to shoot in self defense I don't want to wait for the cavalry with an empty gun...in my city the average 911 response time is around 9 minutes.

2) Under stress I may not be able to reload as smoothly as I can when practicing, so fumbling the reload is a possibility. If I fumble, I'd rather grab a 2nd speedloader from my belt than try to find the speedloader (or, worse case scenario, loose rounds that spilled from the loader) I dropped on the ground. Once the gun's been reloaded I can look for the dropped loader/ammo.

This is just my opinion based on my own practice experience, but I don't use tactical reloads with revolvers. I think they make more sense with semi-autos (though I actually prefer the reload-with-retention technique). Doing a tactical reload with the revolver requires opening the cylinder, pushing the ejector just enough to lift up the fired cases, finding the fired cases, removing them, and refilling those chambers with live rounds. Given the circumstances, I'd rather just dump the cylinder contents and get a speedloader to refill the chambers. Plus it keeps my reload protocol the same (KISS principle).

When I carried speedstrips I often practiced a partial reload, i.e. reload just 2 rounds and back to firing in the event I don't have time to fully load the cylinder. I'm inclined to agree with those who say one is more likely to run out of time than run out of ammo.