As much as I like and respect Commodore, I don't know what the f were they thinking while making CD32. It's such a bad console and it even looks cheap - the plastic is so lame that just looking at it hurts.
What were they thinking was, we need to make something that isnt too expensive so hopefully we can sell enough to stay in business.
All in all, it's not bad. most game systems from that time are hard to look at.
So, to the original questions.
Is it worth owning one? Yes, depending on the price.
Is the controller good? Yes, the Commodore controller actually feels good in the hand. If you arent an animal and take care of your stuff, it shouldnt break. The Competition Pro is okay, but what it uses as contacts for the buttons is crap and will require opening it at some point to clean them or bend them to make them work well.
Do games load up quickly? Not really. It's not slow but it's not a speed deamon by todays standards. Remember, it's from an early era where CDs were just starting out.
Is it well built? Yes and no. Plastic is cheap but at least wont yellow. Usually you find them missing the back panel over the expansion connector. This is because companies like Scala used them in the rack mount video equipment they sold and had an SX-1 connected there. The door mechanism feels flimsy and was an obvious problem. Older systems have the door flat in the back, later ones add plastic over the hinge to make it stronger so I suspect the flat versions (along the back of the CD door) could have an issue cracking along that due to the springload of the door hinge. Therefore a unit with the extra plastic (seen as a raised area along the back) is preferable.
Are NTCS games hard to find? Yes. Since Commodore was so in the hole they never managed to get enough into the US so most sales were in Europe therefore games companies made most money with PAL versions.