Speed affects older drives. The SegaCD won't read discs not burned at 2x or slower, for example.

CD-RWs won't work!

I haven't found speed to affect burning.  However, TransMac (with good images) tends to be very effective (via Windows).  That's not always true.  I've had really weird burn failur…

I like to check a flaky or unknown drive with a commercial (pressed, not burned) audio CD. If it won't play without skipping, the drive may be toasted or require thorough cleaning…

Use CD-Rs, preferably 650MB.