Okay...
Constructively: It's all about what you want. If you're happy with it, it's good.
Having said that... it looks really boring to me, and I envy the space you have and would do a lot more with it. I'm not being nasty, just saying you have a lot of round-and-round (of which I'm typically a fan) and not much else. I like mainline running more than many, but having some better space for scenery, industries, etc would be great. And it's not a "choices" scenario - you've got plenty of space for it.
Most critically, you have a huge 6-8' x 20' space in the middle that might be good for a large public display layout, but is wasted on a private layout, IMHO.
I've attached a quick mockup of something else I might do in that space. This is very rough only. You have plenty of room to double-track the mainline, add more spurs, run an elevated second loop around the outside, etc. This is just ONE variant on what else you might do... This has 32" radius, at least 3' wide aisles... it's not cramped, nor does it require super-tight radii or anything... But the concept of "use the space a bit more" is the key thing.
Hey... you asked for constructive...