Experiences in public sector service logic - DMV vs USPS

In the US it is common to complain about the lack of service quality at the Department of Motor Vehicles (DMV), the organization which administers driving licenses, vehicle permits, and many other traffic-related permits. Everyone likes to share their stories of long wait times, crowded waiting rooms, and rude service. It often is used by stand-up comedians as the archetype of lousy public service. However, my own experiences have been very different, in fact mostly the polar opposite. Maybe my expectations were set low, but every interaction I have had with them I have found the service to be excellent, on time, and efficient. As a service organization, DMV has to handle numerous challenges that less common for most for-profit organizations. DMV needs to be able to serve every citizen, regardless of age, location, social group, language, income, disability, financial capability. They also support an extensive network of office locations, while also providing numerous on-line services. Also, as for most government institutions they need to adhere to a myriad of complex regulatory requirements. I believe much of the reputation for poor service is a relic of the past - when service possibly was far worse. In fact, it is clear they have spent considerable effort on improving the customer experience. They have shifted many services from in-person to on-line. They offer a comprehensive on-line system for scheduling in-person visit, when such in-person visits are needed, such as for a driving test. Inside the office locations, they have set up an efficient "flow system" - where customers are quickly triaged to different service clerks. They also appear to have close tracking of customer throughput and wait times, and make this information available to customers - for planning and expectation setting. This model has some similarities with supermarket checkout these days, where a customer can choose between different lines depending on number of items purchased, and their preference for self-service - but I find the DMV model to be more efficient and professional.
       For a public organization like DMV, it is not clear what may be the opportunities for extensive resource integration or co-creation. For an example of simple co-creation (but less successful), I will turn to the US postal service (USPS). In recent years they have expanded the ability for customers to print their postage using a home printer - and customer then can simply drop off the package to the post office, thus significantly reducing the wait time needed. However, while the effort is well-intended, it unfortunately works poorly in practice. I believe one of the key reasons is that it is still far too difficult for most customers to understand what postage to select when creating postage at home. The USPS maintains numerous (5+) different parallel pricing systems, depending on many obscure rules and exceptions for package size, type, dimension, weight, destination, content, etc etc.  Furthermore, while the DMV online services are excellent, the postal services' online services are confusing and hard to use. In contrast, most for-profit postage/shipping firms, such as FedEx, have excellent online services that makes the shipping process easy. The USPS service would benefit from a better integration of the pricing model with the self-service process, to achieve an overall more customer-focused experience.