Different strokes for different folks. There are a gazzillion suggestions here, some help some are anecdotal, others are throwing money away yet some swear by them. Read, and try the inexpensive things first and venture out the more expensive things if you continue to be unhappy.
75% of the improvements you're going to get in a 915 that doesn't need rebuilding is had from a good rebuilt coupler, new bushing up front and a solid adjustment. The rest is an expensive slippery slope.
Or get a G50.
