I hurt my back over the weekend so wasn't up to trying the multi-positional thing and wasn't able to look for my tripod, however, having played with it generally over the weekend, I am very underwhelmed. I am getting WAY more bass from my center speaker, than the subwoofer even with it set nearly at max volume (-10 to -15). The sub is working, and I can hear it making some sound (I can feel it if I touch the cover). If I play something bass heavy-ish, and then alternate between sub on or sub off, I can barely tell the difference. My wife said the same thing.
I would wait until you are fit and able to spend a bit of time to properly set it up. I would be very surprised if it performed worse than your old sub and the difference that poor setup can make is huge. Make sure that it is connected and set to the default settings as recommended by the quick-start guide ie. gain at 1/2, phase at zero, low pass filter at disable/LFE. Set all speakers to small on your AVR, crossovers to 80hz, and the low pass filter to 120hz.
If your MLP is in a big null, then it will sound like poos at that location. Does it sound louder/clearer when you sit in different places around the room? Best way I have found to isolate issues is to disconnect all of your speakers (easiest way is to unplug the negative terminal and push it out of the way so it can't contact any ground), and play a song/movie/sound file that actually features good quality bass ie. loud and has <20hz - 80hz reaching/sweeps. If it sounds better at some locations, do the sub-crawl mentioned earlier. If you hear nothing at all, you probably have a connection or crossover setting issue.
Once you have the approximate location right, then re-run YPAO, then mess around with fine-tuning gain/phase/crossover levels.
I have also heard Yamaha AVR's have issues with low sub pre-out voltage that leads to volume issues, but if you are already using a Y cable plugged into both LFE IN L/R RCA ports on the sub, it shouldn't be an issue.