I have had real good luck with Ale yeasts in apple Cider... I will continue to use them for that. I haven't really had any trouble with my apple ciders clearing properly with Ale yeast, or weird, off flavors in them either - which is why I started out with an ale yeast in my Perry batch.... They have also cold crashed reliably.... although I pasteurize my sweet hard cider rather than filter sterilizing... I have no doubt that filter sterilization would work just fine after cold crashing and carefully racking off the lees, though....
Perhaps Pear is just different from Apple.. It probably needs to be treated more like a fruit wine than like Cider.. Thinking about it - I wouldn't use Ale yeast in Raspberry or Plum wine..... This stuff started with the raw juice with an SG=1.094 and a whole lot of acid. Pear is also notorious for clearing extremely slowly... and it is living up to that reputation...
I didn't get anything off the pear tree last year... so there won't be a 2011 batch.

Apparently, it doesn't bear every year.... Maybe 2012 will bring a good harvest of pears....
Thanks