Re: Roland or Yamaha?
In my opinion, Yamaha snare and toms sound like real drums while Roland toms sound completely electronic. And yes, I've played both side by side. I own a Yamaha DTX535K and wouldn't trade it for any model Roland. Plus, Roland's additional pads are extremely expensive compared to Yamaha's pads.
Go with the Yamaha, you won't have a single regret.
My 2 cents, Defender