But I'm still not sure which way I'll go. My biggest tank (for now, at least) is 10 gallons. I also have 3 6-gallons, and a 2.5-gallon at work. I'll probably just "settle" for low-tech, non-Excel tanks. I'm not big on pruning and rearranging on a weekly basis. Like you, I much prefer a (somewhat) worry-free tank that I can just enjoy.
If that is the case then I would strongly advise against a DIY CO2 setup. Excel is great for small tanks though, so you could definitely consider it. You could get away with a water change every 2 weeks. The nice thing with doing excel is that you can grow some of the foreground plants that you typically can't in lowtech tanks, such as Hairgrass, Glosso and HC. I think either HC or GLosso can grow in a low-tech tank but it usually grows longer instead of along the surface in non carbon supplemented tanks.
However if you want the least hassles then yes, non excel, low tech cannot be beaten. Just make sure you plant very heavily if you're not doing water changes and that the plants are all healthy and growing before you stop with the WCs. Btw, Anubias Coffefolia and Java Ferns make an amazing combination in low-tech tanks (as do Vals).