Ok, so this is for a bb51, not the BB71, but they are similar items, and it may be useful to someone...
Bought the bb51 as part of a replacement crank set as the teeth had worn out on the previous crank and on the inner ring were not replaceable.
Replaced a serviceable old style bottom bracket to fit this one (as the new crank design includes the bottom bracket axel, so no choice). Previous bb had about 8,000 miles on it.
Fitted this BB51 about 600 miles ago. It is now not serviceable due to excessive wear in the bearings, means the cranks and pedals move in ways they should not.
I have disassembled the crank/bb and the play is in the bearings in the cups, all the other items are tight and not worn. The grease in the BB had a rusty tint to it, despite the bike and bb cups being non-ferrous, indicating that water was getting in to and corroding the actual bearings/race/cage.
I regularly ride on tracks, through puddles etc, but the bb has not been power washed.
So if you want a bike that you can ride after a few miles i would consider another BB system.
To me it looks like Shimano have taken a good robust BB solution and replaced it with another, much worse system.