Lagers are so much different than ales. I've done about six so far. This latest time, I brewed a Helles Bock that took about a month to finish out (may have been done at 3 weeks but I'm in no rush and don't like to take a ton of gravity samples). I harvested the yeast from that and brewed an a BoPils and then an O'fest about 5 days later. SG on both were similar. The O'fest finished after about two weeks, all at lager ferm temps, and the Pils took another 10 days just to get to 75% attenuation, at which point I bumped up the temp to get it to finish faster. Both got pitched in basically the same manner with the same generation of the same yeast, aerated identically, etc.
I guess I'm learning that it just takes lots of patience.