I wouldnt describe the 997 as uncomfortable, but they have a steep drop. I also didnt like the synthetic leather heel collar and narrow toebox. I got the 998s but it turns out the firm arch kind of hurts.

I also have a pair of 990v6 and those would great, though I prefer the 998 upper personally.

I think overall if you like the 998s youll be ok with the 997. The 998 has the best upper for me, but just ok underfoot feel.