Thanks Derek - but how did you know I was using the extension?! :shock: You're quite right, tho.
A few reasons:
1. it's a lot of work shifting from extension to no extension on my lathe and I do more needing it than not;
2. vibration was annoying me when using the extension since I moved the lathe to a new location and I really wanted to get it sorted (I think it is now, more or less - I'd blame the bruising in this one on bad workmanship); and
3. I've had to set up lights so I can see properly, and I set them up for use with the extension - when I turn the head toward the bed, I'm working in my own light.
And - 4. Most of the turning I've done since I got the lathe has been needed the extension and I now find it awkward to turn over the bed (actually, bars on mine) - mainly because they get in the way of the handle of the gouge if I try to cut steep sides (which I generally try to avoid doing because I'm not good at it!).
I think the long-term solution might well be a free-standing tool rest. annoyingly, there is one in the workshop but its lowest setting is too high for mine, and it's not mine to cut down...
edit = sorry for rambling answer, but I've been struggling with the lathe/ extension the last week or so and your question hit the nail on the head!