Personally I think Strava is a pretty good tool to use in terms of interval training, I think its helped me to increase my average. My only issue is I maybe try too hard everyday to get PR on the segments, rest is the key here. BTW no expert and some will disagree with me as well, thats fine but I do read alot about interval training, sprinting etc, Strava fits the bill does it not?
Agree on the strava assisting intervals. On some days though when the wind is full on headwind I dont bother on a section and treat it as a rest day. TL and wind can ruin a strava effort.