Hiking Boot durability?

Some of the recent equipment-related threads have me thinking that I can't recall ever seeing much discussion of people's experiences with footwear. I know that the choice of a hiking boot is highly personal but I'm curious about what people consider to be a typical lifetime of a boot (probably better to estimate this in miles rather than time since some folks on this board hike more in a month than many of us do in a year). When I first started hiking many years ago, I bought the more "consumer" brands (Timberline, Land's End, etc.). These were typically very comfortable right out of the box but tended to wear out pretty quickly (especially when spending a lot of time on granite or other rock surfaces). I've got a pair of Merrill half-heights that I use for shorter day-hikes out here in the east (they're comfy now but they took a VERY long time to break in) and a pair of Oboz that I've yet to fully break in but my favorites are a long-discontinued model of Scarpa's that took a little bit of getting used to but which I quickly grew to love. The soles are still in pretty good shape (although I think they may be just starting to lose some of their grip) but a year or so back the seams on the uppers started to loosen up with the expected effect on the once-quite-good water resistance.

FWIW, since we only get to do "serious" hiking on our vacations, I probably put about 200-300 miles a year on the Scarpa's (can't recall how long I've had them without checking my receipts log) so I'm probably approaching the 1000-mile mark. I'm guessing that that's pretty good, durability-wise but, for both sentimental reasons and the fact that Scarpa doesn't seem to make a shoe quite like this one anymore, I'm wondering if it's worth finding a shoe-repair store to tighten up the stitching on these.