I have the O-Bug, and the Expression, and a lot of cartridges. I too have reached the point where the new cartridges are starting to be repeats of current images I already have, just a different artist's style.
I had the same problem when I was a hobby demo for SU. I loved being a demo, because I love teaching people how to craft and watching them "get" that they too can do this. I stopped being a demo about 7 years ago and I have enough stamps to cover just about any occasion. Now I get to teach again, within the past year a Joann's opened in town and I'm teaching scrapbooking (paper, stamps, punches, glue, = fun) and a new class "How To Use Your Cricut" (there are some samples on my blog that I use for the class)
I was gifted with the little Cricut, got hooked of course, but with my arthritis I find it easier than my Lovely Old Red Sizzix (which has been gifted to a Kindergarten Teacher along with half my dies). I kept the dies that I didn't have a cut on a cartridge like it.
Positives about the Cricut, for me, I can cut any size I want (granted there are limits based on the machine, all tools have positives and negatives) and in any color I can find or make, pre cut dies come how they come in the package. Great for my hands. I find the Gypsy easier to use than Design Studio, I failed to purchase any of the other programs and that's because I just wasn't paying attention, I kept saying later, later, I can find what I need on cartridges.
The Cricut Cake machine has allowed me to get back into cake decorating which I stopped because of my hands. I figure out the designs for the cake on my Gypsy, then plug it into the cake and cut. Now I can cut fondant like paper, it's fun, and I enjoy making cakes again.
I found an awesome deal on the Yudu machine and my family and I are experimenting with printing shirts for our own use, the Cricut makes this possible because of the ability to make cuts, reverse the image, cut out in vinyl, and then attach to the screen.
I don't have the E2 or the Imagine, and I don't have every single PC product ever made, and I've been acquiring this stuff for a very long time, so long that like my stamps, most of my cartridges are "retired" from production but perfectly useable.
Negatives - space all this stuff takes, money and time invested in purchasing (always on sale, but still money spent), and like all hobbies you got to be sure you love it and that the shopping/hunting/spending doesn't turn into an obsession.
Thanks to the very artistic and talented posters on this site and others, and all the offerings on You-Tube, I have learned so much, I'm trying new products, new styles, new ideas. I appreciate all that I learn about craft supplies and the crafter's who use the product.