Bad Compression tube in a HW97k

I have a HW97K in .177 which I purchased last summer for FT. I happened to stumble across Paul Watts web site for tuning airguns. His assessment for a bad compression tube was if the gun shoots in the low 800's with cpl's instead of the 900 or better. My gun shoots cpl's around 840 avg. This translate to around 12ft/lbs. I always felt that this gun was a little low on power but a FT tune usually goes for around 12 to 13 ft/lbs. Isn't 900 ft/sec to hot for a FT (14.2 ft/lbs)? Do I have a bad compression tube? Other than reduced power is there any other bad problems that will result if not repaired? Should I send the gun to Beeman for warranty or should I just keep shooting the gun and not worry about it? After recently reading about all the manufacturing problems of AA and now Weirauch ( I also bought a PE last summer)I feel now that I should have bought a Chinese gun. At least you know its shoddy work rather than paying for quality and finding out its no better than asian guns! Any advice on what I should do is appreciated.