IMHO, MXL-RG03 is one of the "reference media", so many writers can burn MXL-RG03 without problem. Of course there are some exceptions. Plextor PX-716A with earlier firmware (1.03 or before) is bad with RG03 (PIEmax > 100). Panasonic SW9573C (Firmware APG1, APM8) is really miserable (PIEmax > 1500 at 8x area). Hitachi-LG GSA4120B is not so bad, but not so good (PIEmax = 60).
Here is a scan of MXL-RG03, burnt by LITE-ON SOHW1673S@1693S, 8x speed, scanned by Plextor PX-712A@1.07. As we know, the quality of LITE-ON drive is not so good. But this scan graph is amazing.