We did do all of the lab caches. I think they are a good idea, but you are only going to get something out of it if you stop to interact. The one that I was looking the most forward to was the Sugar Shack just because I love sweets. I was highly disappointed in that one. We came in the middle of the afternoon and went into the store really planning on buying something. We looked around and I thought the prices were high but I probably would have splurged a bit and still bought something, but the person behind the counter never interacted with us at all and spent most of the time on the phone taking care of an order, but even when she wasn't on the phone, she didn't seem to care that we were even there or might need some help. We decided that since we had just eaten lunch that we weren't really needing any fudge any way, so we decided to just leave and let it be their loss. We loved the tour at the Rainwater place and I talked Stan into going into the Rock Shop even though he hadn't initially wanted to go, but we both ended up really enjoying the visit. The lady was very nice and informative and ended up inviting us to take a lucky rock out of her basket which we both carried with us on the challenge....I guess it worked. LOL. Neither one of us are wine drinkers, so we just got the code off of the brewery one. We visited the place with the bronze statues and I don't think that they really had anything officially set up for the geocachers other than the code, but we ended up being mistakenly directed to see a large bronze statue in their workshop area down the hill because they thought we were part of what was probably a veteran's group that was seeing the military type statue. I think that stop could have really been a good one if the business was willing to be more interactive with the geocachers.
For the geocoinfest, I don't really have any recommendations for places, but I would make sure that the businesses are excited about the opportunity to interact with the public if the lab caches are centered around businesses.
One of the things that I think is interesting in Kemah area are all of the pelican sculptures. However, these may be better suited for finding them with a Wherigo rather than a Lab cache. We had fun taking a walking tour in Bastrop of the Historical homes following a Wherigo and the same type of thing could be set up following pelicans in Kemah.