Having rented in London for around 15 years in many houses. Moved every year because the landlords\/houses were so bad or prices rose at unreasonable rates.
This has been by a mile the best landlord I have had and because of that I stayed in the house for 6 years. The quality of the place was great and the price very reasonable with minimal rises every year.
They are responsive, fair, quick, communicative and try to deal with reasonable requests such as additional cycle parking or new equipment.
When there were issues they were resolved extremely quickly, such as a new roof that was fitted a couple of days after a leak or a new washing machine that was delivered the day after the other one broke. The shared areas were well managed with a good system for storing bikes in a common yard introduced.
Renewals and the administration side of things were simple and fair as we received almost all of our deposit back.