My ESCO strut started leaking at 50-60 hr TT.  I decided to replace the strut primarily to have something that was currently in production.  The only negative was the strut was about 3/8 inch longer in the fully extended condition and I had to relieve the nose gear door rear closeout.  Fortunately this was done before paint.  The very big positive was the new strut taxies much straighter and requires very little right brake to taxi straight and turns are much smother.