I have both brands currently running in my tanks. Both are good products and I haven't had any trouble with either of them. I like external controllers because you can adjust the temp from outside the tank... A small convenience.
I haven't got it yet but i plan to get the ViaAqua titanum. It's going in a sump so no one will see it, and it's less likly to break then glass. Aslo the remote temp dial is cool.