Many thanks to all (esp. Gerard from sodaclub) who replied with feedback and advice. After almost 2 weeks, I'd say sodaclub has been an almost unqualified hit. It really is easy to set up and I like that I can control the carbonation. The seltzers have turned out perfect. I originally got it for the seltzer, but the soda samples in the kit have turned out to be really surprisingly good. We've gone through 4 flavors so far, with the cola especially notable. Not too sweet, and lighter than regular Coke.
My only (little) quibble so far is that sometimes an entire bottle will stay carbonated to the last drop, but sometimes not. It also looks like I may have an issue with a defective cap, but sodaclub has been prompt in dealing with it (I hope). I also wish that their enclosed DVD/CD had a video demonstration of how to first set it up, rather than a graphical demo, which still left us with a couple of questions (this last one is for you Gerard).
I would recommend it highly (and have done so to my fellow seltzer drinkers at work).
I also purchased the sodaclub.com kit based on the previous thread. I agree that it works great - the seltzer is wonderful, and the convenience is... well, convenient.
For myself, seltzer with a squeeze of lemon or lime is generally all I need. But for the kids, I wanted to try some of the syrups. I got both the regular and diet sampler packs. Then I looked around for some other sources for syrup and found some that I'll report on below.
One of my kids wants Coca Cola. Period. Not Pepsi, not RC, not nothing else but Coke. I had a hard time finding the syrup on line - I did find a source and actually got a 1-liter container to try - but it was extremely expensive, and definitely not worth the effort. The local Coke bottler won't sell just small quantities of syrup - they want you to rent all kinds of equipment, or establish a commercial account. I would love to find a good source for coke syrup - if anybody has any info on this, please share. I'd especially love to see Mexican or kosher for Passover syrup, as they use sugar instead of HFCS.
The sodaclub.com syrups try to be healthier for you. They use about 1/3 of the sugar as commercial sodas, but they try to make up for it with a bit of a sugar alcohol, sucralose. My kids taste this right away and don't want to drink any of the flavors. Too bad... The sugar itself is listed as sugar and/or HFCS.
What little soda I do drink is diet since I'm diabetic. The diet sodaclub.com syrups use Splenda, which has it's own aftertaste - better than Sacharin or Nutrasweet, but still takes some getting used to. They also still contain the Sucralose. I've never liked super-sweet, cloying drinks - what soda I do drink tends to be of the clean, refreshing type, what in Japanese is called "sappari". My favorites are from the local (Massachusetts) Polar company - Dry Orange, Tonic, and their Tom Collins mix (no gin). Based on these tastes, sodaclub.com's diet Pink Grapefruit is quite drinkable and refreshing. The others, less so.
I tried getting some medicinal quinine to use as a flavoring for Tonic - no go. The only stuff I could find was a red bark substance. Using it directly, the quinine flavor is there, but the extreme bitterness of the bark makes it unusable for flavoring purposes. On the other hand, if I had malaria, I'm sure I'd be happy to drink gallons. Maybe I'll try boiling some in water and filtering through cheesecloth.
I went to Prarie Moon at http://www.prairiemoon.biz/, and bought some of their RIO flavor concentrates. These are flavors only, and you make the syrup based on your choice of sweeteners. I bought the Black Cherry, the Ginger Ale, and the Cola concentrates. I thought they were all very good - but the kid still won't go for the cola. The Black Cherry compares favorably with Dr. Brown's. I experimented with sweeteners, and found that my favorite mixture was about 4 of the packets of Stevia and about the same amount of Fructose in a liter of soda (with 2 capfuls of flavor concentrate). Splenda and Nutrasweet give me the heebie-jeebies - not very scientific, I know, but I just don't like them.
This is all just for fun, and I don't believe that any of it's going to be cost effective in the long run. If I never buy another Polar soda or bottle of seltzer, then certainly, the sodaclub.com will be worth it. Other than that, I'm buying stock in the Coca-Cola company!