Have you ever shot a PTR or other 91 clone before?
They are great rifles - not knocking that - but the ergos kind of suck. They are heavy (most 308s are) and the button mag release really sucks. The safety engage/disengage is not very intuitive. I put it more in the hunting rifle class - not something I would want to reload under stress. AKs have better ergos. You could always pay a gunsmith to put the original AK-style paddle mag release on one to make it more like the original HK91...which is actually a huge improvement. Having owned one before, I probably would not own another. But, they are reliable and surplus mags are dirt cheap and in the $3 range. Optics mounting is a challenge and they are not setup for a true cheek weld with a scope and the standard stock. Iron sights on a 308 kind of defeats the purpose.
I would recommend trying one out before diving head first into the platform.
If I wanted a $1000 308 semi-auto right now I would probably look for an AR-10. Just my opinion...