Apparently it’s not been very difficult for my friend to choose the better cello. He played for about 5 minutes on one and no more than 10 seconds on the other one and then it was clear…
The Stentor Conservatoire is the glorious winner.
The reason for this was (in his eyes) simple: the sound of the Stentor was much expandable and much more cello-like than that of the Roth&Junius. As I had noticed before the A string of the latter was a bit scratchy and kind of annoying. My friend thought so too and he added that with some high-quality strings and maybe a smaller bridge, the Stentor would make an exceptional student instrument for a bargain price.
To make it a little more exciting, I asked my friend to guess where each cello had been made. It was really interesting to see how he thought that the better sounding one (the Stentor) was made in Germany or at least Europe and the Roth&Junius was made in China. Funnily enough, it was the other way round.
So what I have learned from this whole thing (which I am glad that it’s over now): You shouldn’t judge an instrument by its origin. Chinese instruments can be good, and if an instrument has been built in Europe, it doesn’t automatically make it the better one. Also I’d recommend that you (if you’re a beginner) to have your options tested. Ask your cello teacher or a violin maker to check the instrument. I probably would have chosen the Roth&Junius, just because I fell in love with its lovely colour and because I thought that maybe the sound would improve. I’m very glad to have asked for help. Plus, I hope the last few entries on this topic may help you to make the right decision, too!