I finally learned my lesson today - the hard way, as usual.
If you don't like something about your quilting after the first pass, trust me, you won't like it any better after the third and it just takes longer - much longer - to rip it out.
I loaded a blue and white top today with a dark blue backing. I had a navy thread in the bobbin and a cream in the top - that was my first mistake. While you can get away with slight tension issues on many fabrics, white isn't one of them. I tried, very hard, to convince myself that the bobbin thread wasn't showing on some of my points. I told myself it was just the needle hole which is more defined on white fabric. It really wasn't THAT bad, but I couldn't live with it and unloaded the whole thing and ripped it out.
I'm really not a perfectionist, but some things I can live with and some I can't. I'm really glad dust doesn't bother me in the least....