Centrally located to everywhere we went during our stay - Rosemead, Canoga Park, Santa Ana, Beverly Hills, Little Tokyo - which was fantastic. We arrived at almost 2am due to the long distance drive and Frazer greeted us anyways.
Ceiling height was not a problem for my bf who is 6'2" and sports a pompadour. Plenty of space and as it's downstairs under the main house, it's cool temperature-wise so we didn't have to use the air conditioning at all. We kept the windows open in the bedroom and bathroom even at night for some fresh air to circulate. The apt is well lit by sunlight and interior lighting.
Keep in mind there is no tv which we found we didn't miss even though we usually have one on during hotel stays. We had an iPad and signed into the wifi instead. No microwave either. We mostly ate out anyways, but there is a stove and pots/pans. We used the Keurig every morning and that's as much as we needed the kitchen!
Bring extra towels if there is more than one person staying although I'm sure you can always ask for more. We really didn't find ourselves lacking anything. Even street parking was plentiful.