I am actually in the process of making a new layout.
I went to MTH Scaletrax with a few Ross switches in the mix.
Scaletrax has the best flex track period.
It is also by far the smallest rails in O gauge.
Yes, there can be issues with the switches, the fixes are well documented and easy to do. The switches all have anti-derailing from the factory but it's not going to throw, it just lets cars push the rail aside to pass back through. Very Light cars could be an issue.
Yes, there is a limited selection of switch types; O-31, O-54, O-72, #4, #6, left and right in each.
That is why I determined how to mix Ross Switches with Scaletrax. Ross has every switch I've ever seen. I got a pair of Ross Ready O-72 Wyes.
I have used Realtrax extensively in the past and will re-use it in areas out of sight. My biggest complaint with it is the noise, but it's not quite as bad as Fastrack.
Realtrax Switches can develop issues but I've always been able to fix them. A common fault is the springs popping off the tree letting the points float a bit. Put the spring back in place and glue something flat on the end of the post. Problem never comes back.
Note there is one spring for each direction of throw, they need to both be correct.
Feel free to email me if you need more data on the switches or fixing open circuits in the track power.