I've got the three-bag set too. I use them for commuting, shopping, and bringing extra stuff along on joy rides. Very functional. Holds lots. You seem to be able to carry any weight. Doesn't impact bike handling. Saddlebags are narrow (when not expanded) so lane splitting isn't impeded. Attacmentment to bike is firm. Lots of handy side pockets to put small things into and keep organized.
Unlike other posters, I find them a big pain to take on/off. I probably haven't found the magic attachment method, but mine are tied/bunjeed several ways. it would take a a minute to take off and 10 min to put back on. When you have the three-bag set, they are all attached together, and if you did remove them, you'd have a bulky awkward thing to lug around. I leave them on all the time. The tail bag is expandable, but a little awkward to expand/unexpand. It loses its shape when expanded, and if there's nothing in it, it gets droopy. So I rarely expand it unless there is a specific need. I have a tiny padlock that I use to lock closed the tailbag across the zippers. It's by no means secure, but it stops the (very) casual theif. There is no way to lock closed the saddle bags.
I've just ordered a topcase to replace this set. Although there is probably similar overal storage capacity with both solutions, in the CoreTech solution, its spread over three bags, and not convenient to carry larger items.
