I can't believe I saw this post. I was just thinking about how my opinion has changed over the past year. I used to only use aquatic setups for triturus and Notos. I have always been very happy with them over the years and was a little reluctant to try the terrestrial setup. But last fall I got juvie marms from Michael Shrom, and put them in my very first terrestrial setup. At first it was a huge pain to feed them, but as they grew they began eating from my hand just like my aquatics do. I have been really pleased with the whole experience. I voted no preference, here's why:
Terrestrial
I kind of like the way that newts look when they are terrestrial (drier skin), maybe because I am not used to it. Since i have larger newts I can feed them easily on land or in water. If i need to take them out of the tank for some reason, it is so much easier to catch them on land than in water. As far as maintinence goes I honestly haven't done much except spray once or twice a week (depending on humidity in the house) and replace the substrate twice since last fall (which is really just dumping out and then dumping new stuff in). The newts seem pretty healthy and happy to me.
The major con to this setup is you see the newts much less. (mine do come out however when the lights are really dim).
Aquatic
The main plus here is being able to see alot of action from your newts. No matter what time it is I can usually look at my aquatic tanks and see a newt hanging out somewhere. As far as maintenance goes, I have been using plants as water filters since the fall and haven't had to worry about water parameters since then. I check them every once in a while and they are always fine. I change water once every two weeks or so, not a big deal. Feeding in aquatic setups isn't a big deal, but my karelinni have been known to chomp each other in feeding frenzies so i usually separate them for feeding, which brings me to the cons,
Catching newts in the water can be difficult sometimes, really difficult. Also, algae is annoying. I usually just scrape it off the glass whenever I change water, but it keeps coming back . . . it always does. So that is an annoying part of aquatic setups.
but as far as i can see, both types are really rewarding. I am interested in trying to mimic the newt life cycle by keeping them aquatic during breeding and terrestrial the rest of the year.
Cheers,
eldaldo