AFAIK, every 240Hz monitor out there is going to be a TN panel, 1ms response time..... So in the spec regard, they'll be very similar
You're basically paying for G-Sync, or not paying for FreeSync (about a 50/50 split in market), with G-Sync panels being in the ~$450 range, starting..... FreeSync is more in the $300 range for a comparable offering.
There's a couple that support neither though.
https://pcpartpicker.com/products/monitor/#D=240000&sort=price
The differing factors are going to be fairly subjective; screen size, build quality, OSD, built-in speakers etc. Don't think a curved panel exists in the 240Hz space yet though.