My Ollie's is about a year old and is pretty nice/well stocked. I think most in this area are newer since they tend to be similar or at the very least they must be run by the same people.
The ones around here stay well stocked and are what I imagine Big Lots used to be at one point. Nowadays, Big Lots just seems like Walmart Lite to me. Most of the stuff they sell seems made specifically for Big Lots and there's less and less stuff that seems actually to be a close out or overstock. Ollie's is almost exclusively overstock, closeout type stuff. Once it sells out, it's usually gone for good or for a good while until they get another lot.
It's not a place you can go do all your shopping at, but it has good deals pretty consistently. We mostly go there for non-perishable food items, personal hygiene stuff, small kitchen appliances, and home repair/upgrade stuff.
They have an electronics section, but it tends to be small and generic stuff. They have a small glass case with pricier stuff, but I've yet to find something that interests me there.
It is nice to be able to browse the book section and pick up a cheap book on occasion and they also have cheap DVDs from time to time.