Trying out different yeast types is one of the goals. I do plan to split 5gal. in the attempt to narrow down what yeast I like. Really trying to keep no more than about two strains on hand for ales and lagers. Mostly using dry but I'll snag a liquid for that special brew. I wanted to look at the small kegs and agree the price just doesn't make sense. I don't mind bottling one gallon.BTW, I do find that 1 gallon extract based batches are great for trying out hops. They are easy enough to brew that I have gotten 4 batches going in a few hours after work. I build them around a 1 lb bag of DME and a 1 oz bag of hops with ~1/4 packet of dry yeast. They can also be a decent option for evaluating yeasts, though you can also do a larger all-grain batch and split it into multiple fermenters.
I have been tempted at times to get some 1 gallon kegs. Small ball lock kegs are pricey and the stainless growler w/ adaptor lid are not a lot cheaper. I am tempted by the 4L Oxebar Kegs from Kegland, but that size is not yet available in the US and stainless kegs are probably a better long term investment. I do really enjoy my 10L Torpedo kegs, but I am not sure I could justify the current $110 price.