The OTop 15 is as close as you're going to get to DR250 performance from an easy to build cabinet in the same size class.
The DR250 works better in the midrange, thanks to being loaded with a ten, but the OTop 15 wins in the bottom end. Like the DR250 it's quite capable of handing electric bass either on stage on the backline or out front on PA duty.
The OTop 15 is more than a match for commercial 1x15s. Here it is compared to an EV Eliminator i.
This chart compares a 1x15 OTop with ASD HF drivers to one of the most popular of the self-powered PA tops, the Mackie SA 1521z.
The Mackie is better below 100Hz, but used with a sub it doesn't matter. Above 100 Hz the advantage of a high efficiency design is obvious.