Depends how many people you cook for. If you’re cooking for less than five people, a slow cooker is worth it (because the tiny ones go on sale for very cheap every now and then, plus take up less counter space), but if you’re planning to host a cholent party for a crowd, a slow cooker will be expensive and take up a ton of space.
Be aware that chulent in slow cooker is different from chulent in pot.
An advantage to slow cooker is that you do not have to leave the hot plate or blech on all shabbos to have hot food for lunch-it’s safer and cooler. You can warm things on top of the slow cooker, or set a timer for the hot plate to just go on before the meals.
(note, you may want to consult your LOR about using times on shabbos and on how to set up a blech for the slow cooker, and how to take food out from it on shabbos).
Once you have it for shabbos, a slow cooker is nice during the week too- set up food in the morning, hot meal waiting for you when you get home from work.
I’ve always wondered why non-Jews buy cholent pots. What exactly are they making in there?
We actually do not have a cholent slow-cooker; my wife makes cholent on the blech. But I think that is somewhat rare.
The secret to good cholent: if you can’t make good cholent, have Shabbos at the home of someone who makes good cholent.