http://www.abbeypro.co.uk/chainsaw-clothing/sip-freedom-progress-and-ultra/showitem-WW-1SNA.aspx
The above (I think they're called SIP Progress) is the best I've worn - only breaking them in just now - they feel amazing. They're going to be my 'summer' pants.
Never tried pfanner - was put off by the supposed tightness around the thigh area.
I also have the following (anyone want to buy some saw protection?);
Stihl Chaps - Great - though can't always climb in them. Try and wear these as much as possible in summer - so far it beats every saw pant for ventilation. I put a hole in from an exhuast too.
Francital Everest's - They're good, but do rip (with small nicks from brush (whatever) - just small tears (if you can notice them), but small tears can lead to bigger tears; you have to keep up with the sewing. Bit too warm for summer. Feel real comfy. Look badass. Mid-budget choice.
Logger King Saw Pants - Hard wearing, heavy duty. Great for winter. You can climb in them - though they are not that flexible, and the crotch will probably tear out. Back on the sewing again. The best for on the ground in winter.
Viltom Raptor Saw Pant - Thick, quite heavy duty outer material - probably very hard wearing pant. Haven't worn them too much yet - they're heavier than the others (and much warmer + thicker) - they'll probably take a real beating, and be unlikely to tear. They'll be my winter climbing pant.
I didn't want to buy so much saw protection but each one had it's slight fault. For me right now - SIP Progress is the best all round. It's always going to be a slight compromise depending on the environment you're working in.
Good luck!