Alternatives to CO2 manifold?

So I've got a 3 keg system running on dual regulators. I need to split one of the lines at least two ways. Do I really need a manifold, or can I just put a T-connection in one of the lines? I don't really see what the difference would be. What are the pros and cons?

I'm looking to hook up a counter-pressure bottle filler. Are there any special considerations for doing that?

T connectors will work fine. That's what I'm using right now with my single regulator setup.

i would not put a simple T inline with a keg for a counterpressure filler because if the filler ever was opened, all the head pressure in the keg would quickly escape, wasting gas. if you wanted to T that line and just remove the ball or pin lock connector while you are using the bottle filler, that would be fine. just dont use them both at the same time. if you had a check valve between the T and the keg, then it wouldnt be a problem.

if you want to make a manifold to go from one regulator to a few kegs, you can certainly use Tees and crosses instead of buying an expensive manifold. a manifold with ball and check valves on each hose is a nice thing to have though.

I was only speaking to a T for a regular keg hook up. Not regarding a counterspressure filler

Thanks guys, this is very helpful! Just ordered some new Perlicks (No more picnic taps!), and I'll be doing some plumbing soon.

A "check valve" is not a gas shutoff device...

Cheers!