FasTrack

I had purchased all of the FasTrack I needed to build a 14x39' layout in my attic. The only drawback was noise. I had built my bench work and was rolling a car on a section of FasTrack. My wife's comment was "I am not going to put up with that". I ended up selling all of the FasTrack $0.50 to the $1.00. The layout is now up and running with GarGraves track and Ross switches.

FWIW, the Ross switches are awesome. You have so much more to choose from. I now have numbered switches, double slips, and a double cross-over. The original plan was a max of 084. I now have 120/128/138 curves. The scale locomotives look so much more realistic on the big curves. The FasTrack switches work great, but you're limited in your choices.

IMHO, there is no true "Bad" choice when it comes to O gauge track. Each may have their limitations, but they all work.

Ross all the way.  There are devices which allow you to trigger the DZ-1000 and DZ-2500 switch machines with command control.

Fastrack is good for a small to moderate layout. The drawbacks I've experienced are the noise and the track geometry - having to use fitter pieces to accomplish what I need to do. For anything larger than 8x12 I'd go with Atlas or Ross track. My next layout is going to use either of those brands. 

I think that Fastrack's limitation on turnouts at O-72 maximum is a big drawback for large layouts.   OK for mid and small layouts, sound can be mitigated.    Here is a recent thread using ballasted Fastrack on a mid-size layout:  Rocky Mountain High

Anything larger than 16' x 20' favors Atlas/Ross/Gargraves to take advantage of wider curve diameter and wider (numbered) turnouts.   It is time for Lionel to introduce a #5 or #6  turnout in Fastrack!

Maybe you should try to design the layout you are trying to build in that space with software (RRTrack, SCARM, etc.) first and figure from there if the limitations bother you?

Comments above are all good. 

The geometry (IIRC) was described as being focused on the resultant center to center spacing being consistent when using switches to go from one diameter to another.  Example, if you nest an O48 inside an O60 inside an O72, you are supposed to be able to easily get the same center to center spacing .  (There might also be consistency possible if you build yard tracks using various turnout diameters.  It's been a long time since I read the article that described all this years ago...  Sorry my recollection is less than perfect.)

The thing that bugged me to no end was how the turnouts were not direct drop in replacements for a curve section in order to create a spur or passing siding(as they are for O tubular).  The little extra "fitter" piece you need to include to mate up to the ballast of the turnout itself causes the geometry to become "impure".  It may be close enough to fudge it with little ill-effect, but it's not a clean replacement.  It isn't too hard to trim the ballast on a mating curve section though if you want to eliminate the fitter piece so you can drop the turnout in in place of a curve piece(without the fitter, an O72 turnout is I believe a direct drop in for a regular O72 curve).  This is helpful if you are adding a simple passing siding to a circle (classic oval and circle sharing a set of turnouts to make the siding). 

Also the O72 wye is really nothing remotely resembling the dimensions of an O72 curve, but it is of proper dimension to support (I think - again it's been a while) making a wye design using a single wye turnout combined with a LH and RH O72 turnout (along with lots of extra straights and curves in between, of course).

Good luck with your decision!

-Dave

I designed the track plan for the 21x26 Sleepy Hollow layout with Fastrack by owner request (now R.I.P. due to owner moving).  

Pros: Built in roadbed-ballasting not required, not that noisy with some sound deadening material.  Wide variety of straights.  Scale looking ties.   Lionel wireless remote control switches and train position features.  Owner made great use of plan and created wonderful scenery.

Cons: O-72 was largest turnout, 6" width (O-72,O-84) between nested curves more than 95% of model trains need.  Limited # of large curves means you can't nest more than 2 tracks side by side (without using filler straights).   Tubular rails and connectors (hard to work with and to separate into powered blocks).  Not blacked out third rail.

I had this same discussion with W&W when designing the South Fork RR.   He thought Fastrack would work better with his Lionel control system.   But there was no way to fit a 3 line main in the space he had using Fastrack.   He went with Atlas for the variety of curves, switches, tie spacing, and simple track connectors.  I used the largest curves size available (108) as often as possible on his plan.   The results looks great.  PS: be sure to check his thread here to see how great layout looks ballasted.

I've reached the design limit of what I can do with my MTH Realtrax layout.   I started with MTH sets that included Realtrax and just kept expanding.   If I knew 15 years ago what I know now about track planning I would have abandoned roadbed track a long time ago.  I've redesigned it with Atlas and plan to sell off all my Realtrax and rebuild with Atlas.   Main reason for the switch is Realtrax curve size limitation, unrealistic built in roadbed, wider variety of switches.  Finally, built-in roadbed track looks HORRIBLE on trestles and bridges.