Thank you, Featuretile and Pinkbikes.

It's good to realise that what's important, in my case, is Altus vs. Acera (vs. Alivio.) I had not thought to compare them using google. That's a real help. I've just done a bit of my own research.

I still don't know what I'm gonna do, but I understand the difference between the bikes now, yahoo! Thanks very much for taking the time to look up details for me, and for your advice.

(One very reassuring thing is that through all the research I've done, I've found no one with a bad word to say about the Globe Vienna.)

Missnomers