I have a 1998 L67 and I removed my balance shaft so I could install a stronger double roller timing chain. The engine has a very slight feeling of worble during idle only but so does my Vette with the stock cam. so... so what. So it has the big cam feel. how bad could that be.. :P If I had a worble at idle because it was a fat cam, I'd be cool right? Maybe without the balance shaft you can simply feel the cam like you would in a V8? yep.. see my point.
I'm not worried that its going to increase over time, that'* just silly.
Techniccally the engine should be able to spin up faster but I don't really think anyone could tell.
I say go for it if you are planning on upgrading your timing chain.
If you like, I'll throw my balance shaft on the scales tomorrow morning and I'll post the actual weight for you.
I say go for it.