I just got back from the range with an HW97 in .177 I purchased used from Dennis Breen from this sites members classifieds. It shoots amazingly tight groups. I did not measure them or take pictures but they were about thumbnail size groups at 25 yards 
The gun is a lower power version 11.8 fpe. so it is real quiet as well. I put a UTG 3x9x40 hunter scope on and it fits just right. It does not seem to care how I hold it or whether it is on a sandbag. I am used to the artillery hold as that is how I shoot my 22lr rifles so that may help. I think the only upgrades i will look at are pellet selection ( it likes the H&N Baracuda FT 9.57 gr.) maybe a better scope from one of my 22lrs. the only odd thing is the twang or sproing noise from the spring, now I know what everyone means when they talk about it, I think it is kind of fun so I will not be messing with it.
The gun is a lower power version 11.8 fpe. so it is real quiet as well. I put a UTG 3x9x40 hunter scope on and it fits just right. It does not seem to care how I hold it or whether it is on a sandbag. I am used to the artillery hold as that is how I shoot my 22lr rifles so that may help. I think the only upgrades i will look at are pellet selection ( it likes the H&N Baracuda FT 9.57 gr.) maybe a better scope from one of my 22lrs. the only odd thing is the twang or sproing noise from the spring, now I know what everyone means when they talk about it, I think it is kind of fun so I will not be messing with it. 