In the beta group we suggested that the Talisman be reduced in power by either making it work only with certain weapons - and adding the 'always hits' power to a particular weapon is another way to do that
-- or by making it only function every few rounds. If it only gives you a 'guaranteed hit' every other or every third combat round that would be much less unbalancing. But then I guess you could mod that by making the dedicated weapon only fire every other or every third round.
I'd still like to see a 'time slip' device given to the Temporal tech field that gives a flat chance for any weapon, even a Talisman guided weapon, to miss.