Hi Tricky,
I am bilateral, 5 weeks apart. The 1st one was weight bearing as tolerated. The surgeon said I have very good bone density that made it a bit more of a challenge to get the cup fit just just right in terms of reaming out the bone (I recall a comment about really having to put the shoulder into the reamer tool), and he had a concern that the 2nd one was not as snug as he'd like, so I was 25% weight bearing for 4 wks after #2. Healing and bone growth are wonderful things. While the restriction was -- well, restrictive for a month, after a couple months, I think they were both at the same place. That is to say, that you are still healing at near the same rate even though you have the weight restriction.
I'm now at over 2 years with my new hips and loving a life of pain-free (at least from hips) activity.
To determine 25% , 50% etc., just step on a scale until it registers that percentage of your weight. That will give you a feel for it.
Good luck,
-Dirk