[MrBasse]

You used to see a lot of caster style robots back when I was in high school, but they haven't been too common lately. They went out of favor and there are a lot of strong opinions as to why. A search will turn up a lot of results, although eh are skewed with the influx of swerve designs comin out lately. So look at old posts.

I'd say give it a shot and see if you like it. Push it around with another drive base, drive over bumps, try running up a ramp, try fine steering adjustment to aim at a target. The biggest concern I would have would be a hard turn when the wheels are pointed in the wrong direction while weighted. We have that issue with our robot cart and it requires some thought to eliminate forcing your wheels to go straight.

All of this assumes you plan casters for two wheels and two driven wheels though.