I'm a frequent flyer and use SEN too, my experiences are identical. The place just works as it should - no drama, no stress, you park the car, walk a few paces into the terminal, fast security, next thing you know, you're sitting at your gate all done in a matter of a couple of minutes.
It only works well because the airport is vastly underutilized. We all want the airport to grow first to 2.5 million and then to 5 million and even more. It will then have car parks that are on the other side of the airport, somewhere to sit will be a luxury and queues will become normal and then the passenger experience will be like all the other airports.
Part of me wants the airport to stay as it is now but that will be seen as failing while 5 million passengers and a Luton experience will be seen as a success.
Enjoy the airport as it is now for if things go to plan a pleasant experience could be a memory from the distant past.