My chillis have been very poor, but they were borderline dead when I got back off my hols (toptip-do not leave 20 year step-daughter the complicated task of watering a plant during the hottest 10 days of the year) and needed mouth to mouth to resuscitate them. And earlier on in the year they had an Aphid infestation!!
The only plant to actually produce any fruit worth while so far is the Bishops Crown, the Habanero, Kashmiri and basket chilli havent really taken off.