I've never removed a deck before so I honestly can't say. But, as far as a chisel replacement, yeah - it would work pretty well. They make chiseling blades for them that have no teeth and are just sharp.

I found it was really good for surgical cuts into the outer shell of fiberglass on my J22 where I was removing rotten core from around a chainplate (with a serrated blade). It doesn't throw dust everywhere like a rotary cutting tool so that was nice. It was also the only tool that would make a dent in removing the teak toe rail on the same boat. The toe rail was attached originally with 5200 and was incredibly resistant to being removed. That rail also covers the deck to hull joint so you can't use the 5200 softener without the risk of degrading that major joint. As it was, the toe rail still came up in many tiny pieces but the chisel bit did eventually do the job. If there is a next time, though, I'll probably use a reciprocating saw and a thin sheet of metal to protect the deck from the blade...it was a major PIA and probably took two of us three hours to remove it (of 7!) and get the deck ready for the replacement . We ended up only replacing the one.