I don't want to bash MTH because they are my manufacturer of choice, and I have had great success with anything they put wheels on, and love the DCS system.
Three years ago, I started a new layout and bought all Realtrax, about $1500 worth. I had used it on my first small layout and had no problems with it, except for an occasional sloppy switch operation which I could live with.
After the track was fastened to the benchwork and all wiring was done, I was satisfied with its solid performance, but the switches began developing problems almost immediately. Slowly, one switch after another started to malfunction. I made weekly trips to my LHS returning defective switches. I am very lucky to have 2 great hobby shops in my area - Catoctin Mountain Trains and J & B Trains. Eventually, I returned almost all of them for exchange to MTH's headquarters in nearby Columbia, Md. There was no problem in doing the swap with their helpful staff.
However, the exchanges were just as bad. Very sloppy workmanship was noted, like pinched wires hanging out of the bottom covers, rail sections that were uneven, switch motors that would hang up, and a little spring underneath inside the cover that kept slipping off the post. It was easy to fix, but once the layout was decorated, I couldn't imagine having to pull a switch up after it was ballasted so I could flip it over, remove the cover, slip the spring leg back on the post and wire it back into the layout.
Finally, I had enough. Of the 16 042 and 054 switches, I could only get 3 of them to perform reliably. The others all had chronic problems, many of them derailing MTH engines or having the engine stop and hang up on the uneven joints. After contacting MTH and meeting with their staff, we came to a resolution and all the switches were returned.
I must point out that I heard from various sources that MTH was having manufacturing issues with some lots, although they did not disclose that information to me. My 031 switches purchased years earlier for my first layout worked well and are still working fine.
I changed to Gargraves track and Ross switches, with flawless operation for 3 years and counting.
Listen to what others have to say about the current Realtrax switches. I think MTH resolved the manufacturing problems a few years back, but it's hard to tell when the switches that you buy were made (unless they have hollow rail). I don't think there's any date code or other information to tell when they were produced. And I don't know what era my switches were from, so it would be unfair to say that all switches produced in the year 200X are bad.
I never had any connectivity problems between Realtrax sections, even after pulling them apart several times for switch removal. (Yes, they are difficult to put together.) The copper contact fingers were robust and only needed to press against the adjoining section rather than clip or engage with another piece. The plastic roadbed made for a solid railroad, and there was no need for cork underlayment, although I used some foam for sound insulation. Of course, these were the solid rail sections.
I have read comments on this forum regarding MTH's Scale Trax, and I think the owners were happy with the performance. It looks good and performs well, from what I understand.
Just wanted to give you some more information to think about before you commit to Realtrax. Good luck on your design.
Mike