I came from a cycling background and started running some for fitness and ended up becoming a triathlete. These times are what I recall all as a triathlete:

2003 I ran 15:12 at the Carlsbad 5000 (22 years old)
2004 31:30 ? at Phoenix New Times 10k
2009 1:09 at Rock n Roll Seattle Half Marathon
2016 32ish in a couple of 10k's
2016-18 hurt my heal and didn't run much for 2 years.
2019 Just ran 15:44 at Carlsbad 5k, the day after a hard cycling road race... Now 10+ pounds heavier than 2003, (But I do have the fast 4% shoes ;) getting serious again and want to run faster than ever as a new goal, within triathlon training, we'll see... 39 years old now, will be a challenge!

I've always mostly just run, I've never run as well off the bike as I "should have". Lots of 45 minute treadmill runs at 7 minute pace. Maybe averaged around 30-35 MPW.

---Adding the session I was proud of, I think probably the best I ever ran (by how I felt) was before Kona in 2007. I ended up walking a lot of that Ironman "run" unfortunately. I recall running mile repeats prior to that, 6x1 mile descending starting mile 1 at 4:55 and finished around 4:40 for mile 6. These I believe were on a 7:30 send-off so roughly 90 seconds between each just standing rest. I did very few sets like this over the years, but I was trying to do something serious for run training for that Ironman. It didn't seem to translate to the big race day.