FWIW I have cordless drills ranging from 10.8v Bosch Li-ion, 12v Panasonic SDS NiMh, 14.4v DeWalt NiCd to 18v DeWalt NiCd and find little to choose between them; the NiCds need to be run flat before recharging, the Li-ions need to be topped up regularly, and the NiMh.... get charged when they're needed...
If you're not going to use them that frequently, then honestly I don't think it matters much what battery technology they use. I went from 14.4 to 18v DeWalt NiCd because once you had the batteries and charger there was lots around that could be picked up bare; I bought 10.8v Bosch because they were small and light for everyday use. Picked up the 12v Panasonic SDS 'cos they were the only lightweight cordless SDS that also happened to look like a a spacetrooper's plasma weapon <shrug>
Do I wish Bosch made a 10.8v combi? You bet. My usage is lightweight and infrequent - much like a hobbyist, probably; if I was plugging 20mm holes in engineering brick or concrete all day long than I'd use my corded SDS - who wouldn't??
Of all the kit that's been linked to in this thread, I think I'd buy the Ryobi Li-ion, mostly for access to the 'One-plus' system. £110? I won't begin to tell you what I've shelled out for all the above...
Cheers, Pete.