Research and lab experience isn't something unique to PhD programs. Lab experience gives you what it says...EXPERIENCE. You can't understand a process as effectively without doing it yourself. I can read about microbiology all day, but if i never plated and stained my own organisms, how the heck will I remember that down the road. Clearly something useful to know as a physician.
Even the limited general bio labs help out somehow. Go over the very basic sciences, including the scientific method. It baffles me that many undergraduate seniors don't remember something so important.
With regards to research itself. The whole process is pivotal in becoming a good doctor. Even though one may not do research down the road, the skills are extremely important. For instance, finding, and reading journals. Additionally knowing which studies are relevant. I don't know if you guys have noticed but there is a thing called Evidence-Based Medicine (EBM). This is pretty much what medicine is these days. Everyone likes EBM. What does EBM involve, well clearly evidence, and pretty much that usually lies with journal articles. Textbooks on EBM encourage MD's to keep up with the latest articles all the time. So it behooves one to have the reading, and analytical skills to rapidly go through these.
Last but not least, research, and labs provides a very useful thing, or at least incentive to be ORGANIZED. The pile system in ones room starts to fail after some time..haha