Something else to consider if looking at OZ vs UA, you should examine the fares you'd typically be flying on *A Carriers ( www.wheretocredit.com ) because often, but not always, UA is more generous for earnings if flying non-UA flights. In the current form of OZ's award chart, many awards are similar priced in both programs. However, depending on your family's flying habits, pooled earnings on OZ may still be better. UA miles are extremely easy to keep active, I wouldn't let that be a deterrent.