Fast food eateries seem to have a wider range of "loved it/hated it" more than sit-down restaurants, likely because service and quality can vary more from shift to shift. My first experience with a Lenny's was at the Glendale location. I am always searching for the best burger on Earth, and rarely find it at chains, even 5 Guys or places like that. Usually the best are at 40 year old single location little greasy spoons.
Lenny's is not a big chain so I would consider them more "local" than a chain. This particular location is tiny with seating for less than 30 people. Half the building is taken up by the kitchen and service counter.
The first time I try a burger place I always order a single, no cheese and what the restaurant considers their basic burger. I do this so I can taste the actual meat patty rather than have it covered up by lots of condiments.
I did so at Lenny's, a single combo with fries and a drink. To Lenny's a basic burger has lettuce, onion, tomato and pickle with a ranch dressing. To me it was bland and mushy and the toppings completely hid any meat flavor. It was completely opposite of my idea of what a burger should be. The meat patty was too thin, the lettuce was too finely chopped, the red onion was sliced so thin it was stringy and the sauce did nothing to enhance the flavor. Finally the bun was too soft.
The fries however were fantastic ... thick and tasty with a nice crisp bite to them.
To their credit, the prices at Lenny's are very reasonable and I would not give a second thought to eating there over McDonald's anytime. The price for a combo meal is about the same.
I considered the service excellent. The counter clerk was friendly and the meal is brought to your table. The lady who served us was super-friendly. I had the impression that everyone who works there enjoys their job. Overall the place looked clean and the retro decor was pleasant.
Note that Lenny's is more geared to be a drive in than a sit-down place and the outdoor dining area is basically some tables in the parking lot.