I've ordered from Puerh Shop probably over 5 times now and I've been happy with everything. However, I haven't ever tried to contact Jim as I haven't had any problems, so I wouldn't know about his responses or lack thereof.
Jim has some good offerings, very reasonably priced, and low shipping costs seeing as he's located in the US. The American Hao bings that he commissioned himself are really great, too.
+ he usually throws in a bunch of free samples with my orders which is very cool.