Cartrodge break-in and counterweight question?

Recently, I purchased a Denon DL-103R. I had read so many good things about this cartridge, I just had to try it!
This is a low output moving coil, so before I pass any judgement on it, how long should it take for this cartridge to break-in?
Also, when I mounted the cartridge in the tone arm, I had to position the counterweight nearly at the very back of the tonearm. Would it help sonically, if I ordered a heavier counterweight?
In advance, thanks for your input.
40 to 50 hours of break-in.

The counterweight should be as close to the pivot point of the tonearm as possible. So, yes you should get a different counterweight.
The tonearm is the stock tonearm that comes on a Music Hall MMF-7. Any suggestions as to a counterweight (what will fit, what would sonically be superior)?
Anyone know if the Expressimo Heavy Weight is still being manufactured, and if so, who sells it?
You can get the heavyweight counterweight for the Music Hall tone arms (Pro-Ject 9) at Music Direct. I bought one for my mmf-7 to use with a 8.6 g Dynavector cartridge.

Music Hall heavyweight counterweight