Re: A three-sun tidal wave!
Human senses tend to rely on rate of change: a small but sharp change in spacetime would feel much the same scale as a large but leisurely one. Gravitational mass is assumed to be identical to inertial mass, so a change in gravity would be indistinguishable from an acceleration due to change in velocity. But if the wave took say half an hour to peak, then it would have to be stonkingly huge, three suns' worth maybe, before one would feel it.
Interestingly, large black holes have gentler tidal forces than small ones, while the effects of a merger are more dramatic. So one stands a better chance of feeling the wave from a couple of supermassives merging than one does from a couple of babies like the two observed this time round. Yes, the tides would dominate with these two.