The microbio module was really good, but it was only a half module (1/8th of the year). The lectures were of a high quality and the labs were interesting and relevent. we also had a compulsory full module in biochem, which was very cellular, and an excellent half module in genetics, both of which would be of interest to an aspiring microbiologist. My year was rounded off with full module chem, half module life on earth (basically a phylogenetics unit), and half module quantitative biology (statistics for biologists. boring but vitally important, I thought the module was well organised).
This term I had 10 hours of lectures a week. I probably averaged 2 to 4 hours of labs a week this terms, but I averaged more last term (even though I took full module chemistry, all of the chem labs were in first term. The chem labs were fun and the best part of the module by far).
Contact hours are... hmm it's weird. we get some face to face tutorials, but most of our tutorials are "e-tutorials", which don't involve face time. That sounds bad but its actually ok. first of all the lecturers are pretty good at giving office hours so you can go see them if you have problems. Second of all, the course makes very strong use of "moodle", an online teaching resource. Through moodle there are lecturer moderated forums to ask questions.
In other words, we don't get much face time, but thats due to the 21st century set up of the course.
The work load has been pretty high but tolerable. With good time-management i imagine you will feel like you are doing a healthy amount of learning, without being swamped. The first couple of weeks of each term have been a bit of a doss, the final couple a frantic rush for most people, but most of us are bad at time management :P
I imagine you will do just fine on a natsci course.