Personally I am not a fan of the built in roadbed track mostly due to the noise.
The roadbed acts as a speaker cone for the rail noise. Hollow rail is an echo chamber as well.
My current layout is RealTrax which I prefer over Fastrack due to rail shape.
Differences in the two that I know about:
Fastrack is a inverted U of rail tabbed into the plastic roadbed (3 tabs per rail I think).
RealTrax is a rail shape (now hollow unfortunately) that is held on by tie spikes.
The spikes are molded plastic and not as strong as the metal tabs of Fastrack but there are a lot more of them.
RealTrax center rail is darkened and less obvious. Fastrack center rail is the same shiny material.
RealTrax roadbed is darker and the ties are a bit farther apart.
Fastrack uses Pins in the rails and this enforces alignment at the joints but in at least one case has gotten corroded and unusable.
Realtrax has copper contacts under the roadbed, these can be troublesome if not connected & separated properly but make excellent contact normally. They do not align the rail ends but I have had few issues with this. Tweaking the end of the rail with a set of pliers fixed them (I bought some used track).
Fastrack pins together and pushes together as pinned track always has.
Realtrax is best connected by holding the 2 pieces in a V with the rails touching and rotating them flat while pushing together. To separate, hold down one and lift the other. The last connection in a loop is the hardest, it's hard to get a good angle between the tracks.
Both stay connected well unless they have been separated several times, then RealTrax can get loose, Can't say about Fastrack.
RealTrax has clips available to lock them together very firmly for this reason, the clips are not needed for most use. I had a loop I stood up against the wall when not in uuse for months (until my wife banished it to the basement).
Fastrack now has TMCC switches.
Realtrax switch command is via an AIU on the DCS system.
Fastrack switches are supposed to be awesome reliable.
Realtrax switches can be troublesome if some issues are not dealt with.
These issues are; loose rails (superglue it down), sometimes the rail points do not stay tight against the fixed rails, it can be either position or both. Cause: little springs popping over the post in the switch. Use needle nose pliers to move the spring back across the post into the notch in the post. I now add a small square of plastic glued on the end of the post (it's flat) to any I have to fix. Never had a repeat fail with or without the added square.
Sometimes the magnets that the reversible switch machine snaps to pull out of the socket. simply maintain orientation and put a drop of gel superglue in the socket, it will be fixed indefinitely.
My layout has been in use for several years now. It is RealTrax, is not screwed down and has no clips except where 2 sidings span the gap at the Crawl-under. And only there because there is no wood supporting it at all for 3 feet or more. (No I don't drive engines across there, it's a couple dead end sidings)
My track has not separated or given me dead spots yet.
Now, If I didn't lose you yet, I really like ScaleTrax for permanent layout.
Real rail shape, much smaller rails and ties, a lot closer to scale. No roadbed tho, it needs ballasting.
See toytrainsontracks.com for some demo video of trains on Scaletrack. Rich sells videos of how to do a layout with Scaletrack too, I like them.