I got divots. Gonna get a re-fret soon. Doesn't bother me playing lead, but I think the lack of proper intonation shows when playing chords. Not real obvious, but I think it will sound sweeter and more precise when re-fretted.
I've seen grooves and flat, shiny fret tops noticeably developing under my unwound strings over the past year after I changed my playing style to include much more lead riffing and string bends. I did get worried and have tried different string brands, but it hasn't made much difference, and I know my guitars are set up properly. I'm trying to pay attention to use a light touch. I did some internet research; general consensus seems to be it's just a normal consequence of playing.
I have my own guitar repair shop, and I hear the same story from my customers... they bring me their guitar for a fret level/recrown saying the frets are a bit worn, but it still plays OK. They can't believe how much better it plays when they get it back!
Most guitars with worn frets can be leveled and re-crowned at least once before a re-fret is needed. Here's a photo of one I did this year. Like Stormin1155 said "They can't believe how much better it plays!"
A couple of small groove on some frets on my Les Paul Special but my SG & Les Paul Classic have both been refretted with Stainless Steel frets and still look like new.
The SG has seen about 2 years of playing and the frets don't even have the slightest mark on them.
I've had my Strat since '01-'02. It was brand new.
After 5-6 years, the fret wires were worn out. So, in 2007, I took my guitar to a shop. To quote the repairman, "some parts were showing wood". I didn't believe him.
As of now, I'd say the wires are worn down to 20%~40% (2nd~17th fret, mostly on A,D,G,B strings). I do have troubles sliding to a note when playing a fast and articulate passage.
I have played on another identical Fender Strat with 90%~100% fret life and the difference was subtle. I am sure if I get the job done, the guitar would play much easier but I think I got used to the frets.