Ok, so I've just started on my lock again and just noticed that they changed these two so that they're now more like the oils you used to be able to coat your weapons with Firestones now increasing direct damage and crit and spellstones increasing periodic damage and haste.
Are they actually any good now? I'm only lvl 70 at the moment, and still using up my stash of wizard oil before my weapons get too high for it to be used on. It's only a 1% in damage increase from each stone, but I suppose every little bit helps?