There are some places and circumstances where the old Atlas double-slip switches function better than Shinohara. I have a few brass ones that seem to function nicely for specific applications. For example, with the Atlas DS turnout, throwing the points one way make it into a crossing. Throw them the other way, and they become a double-slip from all leads. With Shinohara/Walthers, you have to align for a specific lead/departure or you will have a derailment. The other leads are not available. OTOH, the Shinohara look better, and may function better under the right circumstances. With the Atlas DS' you only need one connection, and the switch machine is built in, precluding having to set up two separate switch machines. By the same token, the Atlas doesn't look as good due to the solenoid housing being on top. ALSO, SOME LONG cars and engines may hit the housing when the route is going around the curve, rather than as a crossing.
Double crossovers can save a lot of space, but as has been pointed out, you need to wire them correctly, and the leads have to match with the two main line spacings. Also, if using switch machines, you need to wire the machines in pairs or else resort to double crank linkages to the throw rods on each so the points are aligned correctly for trains entering and leaving the crossover(s).