I had a college coach who was coached by Mihaly Igloi for a few years in LA. He had me do a few of those types of workouts. Physiologically speaking, I don't know if it did any harm or good to me. However, it did teach me how to run fast when I was tired, so I can't see it being all that bad.
Workouts that I did and enjoyed:
--30x200m with jog back recovery (done on a rolling dirt trail by myself, in late february. i put broken sticks in the mud near my finish line to count). 4 mile run to spot, workout, and 4 mile jog back to my car.
2M warm-up
15x100 in 15" with 15" standing recovery, on grass in spikes.
400m jog.
10x200m with hurdles, done on half the track, jog across 50 yard line recovery (me, steepler; 1500 guys did another 15x100)
400m jog
15x100 in 15 with 15" standing recover, on grass in spikes.
15 minute "jog" cool down. we could barely jog and it was more of a jog/ shuffle.
some kid in DE: if you can finish your workout successfully, you'll be able to run under 4:20 for 1600m. Or, you can do what you think is right, and continue to run 4:45 every time you race. If you want to race and run a time in a way you've never done before, you have to train in a way you've never trained before. Man up!