New to the points/miles game here. Recently got a Chase Sapphire Preferred and have about 70,000 points thus far. I've read that booking travel with points through Ultimate Rewards is generally less preferable than transferring points to a partner and booking through them, as you can frequently get better value.

I was looking for a flight on US Air, which translated to about 21,000 UR points on the UR portal. Booking through US Airways' site for the same flight resulted in a 50,000 point cost. So the question here is, what's the strategy for maximizing point redemptions for travel? Either I'm not going about this the right way, or UR points are significantly more valuable in this instance.

Any tips anyone has would be much appreciated.
Thanks