My high mark was over 4,300 miles (in 10 months) on a pair of Converse ABM-400s back in college.
In the mid-'90s did about 3,800 in some adidas Web Techs, I think they were called. More recently, 2,542 miles in adidas Terrex Agravic Flows; 1,801 in Hoka Challenger ATR 6s; 1,507 miles in Hoka Clifton 1s; 1,754, 1,708 and 1,506 in three pairs of Puma Trailfox 4s; six other shoes retired above 1,000 miles in the past decade; and four other shoes still in rotation above 1,000 miles.
Some past threads:
yadoshi 7800 miles in NB 574
At least five guys with shoes over 3,000 miles in this thread: