Depends on what type of camping you do. Sounds like you liked having a black tank in your last one so you might not like a cassette toilet.
I only have a 5 gallon porta potty in my TC. But I like it much better than a black tank for my type of TC'ing. I like boondocking and trips where I only stay on one spot for a few days. I love the ease of emptying a porta potty or cassette. The new ones are very easy to empty, with the spout and vacuum release button.
Just wait - you will get a huge response here. Also check the archives... many discussions have been had about this. And you either love them or hate them, no in between. Kinda like the question "which way should the toilet paper hang?" Everyone has a major opinion about their way LOL
In closing, my next TC will have cassette. We like to winter camp as well and it's a pleasure to be able to use a porta potty or cassette without worrying about dumping a frozen black tank. With a cassette you can bring it inside and allow it to thaw out and dump it with ease. I have no problems dumping mine in a household toilet. Never had a mess or caused an issue with plumbing.