Running the engine on a stand takes care of initial break-in and any concerns about issues - if the price is reasonable.
Utility of the chassis dyno depends heavily on the operator or you, and what you want to get out of it. For full power mid to top end an inertia dyno will show which changes add or subract more Hp for each change. If its got WBO2 tail sniffer you can also see if the AFR is drifting during the pull and things like that.
That said, the mph in the 1/4 will get you pretty close, usually for less money, but depending on how busy the track is, may take longer, and even repeated visits. Plus you get to run the 1/4 mile.
For cruising and throttle response you'll need an eddy-current dyno and an operator that knows how to work it for those things. That's a rarity. Expect to do the street tuning on your own.