I use it.
But first thing you need to know is that for 90% of the problems Access developers face, class module are either overkill or too much work for little gain. The problem is that Access/VBA are object-based, but not fully object-oriented, so that limits the potential of class modules, which is why they tend to get neglected.
Anyway, what you can do with a class module are basically for two things: 1) when you need events, 2) when you need multiple instances of same thing.
Custom events can be declared in a class module, but you are responsible for raising it yourself, and it's hard to think up of event where you really need to be raised that isn't already done by a given form or control's event. In my case, it was an exception because I am able to manually control transaction and thus needed a event to do validation before I commit the transaction (useful for multi-form validation for example).
As for multiple instances, suppose you needed to maintain copies of recordset that has to be presented in a certain way. Using class module allow you to create a "cookie cutter" defining all the parameters you want it to be, then you don't have to worry about it when you declare an object from the class because it take care of all tedious work. Of course, this is only useful for stuff within code such as recordsets, arrays, collections, or a certain type. Class modules doesn't interface so well with controls (e.g. I can't really create a Cascading Combobox class where I can just drag'n'drop into a new form and BOOM! two comboboxes with all the code to cascade properly! [Well, technically, it can be done, but that's beyond the scope]).
It can be also used as an alternative to Type; VBA is kind of pesky with user-defined Types but can handle the objects created from a class much better, so using a class to define a type is a good use as well. I created, out of fun, a class module that defined a signed byte data (which was just an integer but with range truncated to -128 to 127 and raising an overflow error for values outside that range).
I hope that helps a bit.
Tangent: I personally find Collection to be more useful & flexible than array, but that's just me.