Okay, so new tripod.
I took some comparison pics to compare size and height.
Thumbnails are clickable.
(Old tripod : Giottos Pro. Alu. MT 9242 with Giottos MT 7303 ball head)
(New tripod : Giottos Pro. Carbon Fibre MTL 8361B with Giottos MH 1311 ball head)
First one is a size comparison with both centre columns removed.
This is how I break it down to put in my bag when travelling anywhere that requires flying.

This next one compares the new one without column to the old one with.

This has both centre columns - together with heads - in place.
You can see that the new tripod is quite a bit bigger than the old one in this state.

Here we see the height difference between the two without any legs extended. Just opened up at their shortest lengths.

The height difference with lower legs extended.

And with both leg extensions out.

And this one, well the old one never was able to do this. (8+)

As you can see, there's some considerable size differences between old and new.
For the old, I had to stoop slightly when taking images without raising the centre column, now with the slightly bigger head on the new one, I actually have to go up on my toes to look through the viewfinder. Which is a good thing, in my opinion.
The new one is also so much more stable that the one I had too. I couldn't really believe just how much more stable it was. I was had doubts that the extra height would sacrifice in stability, but not in the brief tests I performed with the camera attached.
I'm really looking forward to getting and using the tripod now. I think I may be doing that early next week, so I should be able to report back about actual field use afterwards.
Sorry for the square thumbs, but it's the best I could do and I didn't want to put these up on Flickr.
Mark