I strained my rotator cuff last spring and really had trouble with single hand casting. So I used a couple of CND 13' 6/7 Experts for my chironmid fishing in BC's interior lakes. They were awesome.
Now I agree there is no benefit to actual speycasting and I overheaded with them, but they were a treat to fish with. I used regular weight forward lines and 16-30' leaders. The soft progressive Experts were great even with 15-16" fish.
This year I will be using the SpeyTrackers as they are lighter yet. The biggest advantage (besides compensating for the injury) was the ease and distance of casting. Normally while chironomid fishing I don't cast very far (45') and don't bother to stand up and haul etc. The 13' rod doubled that distance with less effort and greatly simplified casting in the ever present wind. I am looking forward to this season!