I have no hate for the 4X8, but train mfgs do!!! Only the starter sets are designed to be run on them due to the O31 curve limit. The items they push on the market are LARGER than O31 curve so your choices are very limited. I still have my original 4X8 from my childhood and recently "upgraded" to a landscaped 4X10 complete with everything but the trains to run on it. I got it for a THIRD of what it cost to build and its ready to run!! Someday I'll clear off the plasticville buildings and such, remodel it and expand it, but for now it fits my train room nicely.
I've been following this thread with interest and despite my urge not to, I wanted to chime in.
There is nothing wrong with a 4x8 - most of my layouts have been 4x8s. Below are photos of my current layout. I recently just added a small 4x4 extension. Not because I was bored, just because I wanted to.
Personally, I like running "train sets", or at least, train set length trains. I don't like running a million cars. 4 or 5 cars is just fine by me. Not to mention, you can run PLENTY of stuff. It isn't just 0-27 trains. I have scale diesels - SD90, GP9, etc. All run fine on 031 curves. MTH Railking is most of my stuff. I just got another MTH Imperial ES44, have an MTH SCALE Dash 8 that glides around the layout. Some may say it doesn't look good but hey, looks fine to me! Of course, I've got plenty of smaller diesel switchers and the like.
As for steam - I do have the small engines - 4-4-2s, 0-6-0s, etc. I always enjoy running my MTH Railking Imperial Y6B (2-8-8-2 - big engine!), my N&W Williams J 4-8-4, which is NOT a small loco, Postwar steam and more.
Before I built the 4x4 bump out, I could run 3 trains and a trolley. Now I can run 4 trains and a trolley. I have every intention of adding another elevated trolley line in the near future. It may get a bit stale occasionally but I pull another train off the shelf, do some switching, etc and it is fun again! I've been asked by a few folks with limited space for input on getting the most out of their layout. As one person said "You're an expert and jamming a lot into a little spot....."
I should also mention - this has all been done in my basement in my house - a townhouse! Could I build layouts 2 or 3 times the size of what I have now? Sure I could! Plenty of room. Granted I'd have to do it all in stages to keep the wallet happy but do I intend to do it? Nope. Only other enlargement of my current layout I'm considering is taking my club module and modify it to act as a yard/siding but that isn't something that will happen in the near future, if at all. I do plan to add another trolley line, a bump and go in the near future, if a certain engine (not naming names!) in my collection will keep running and stop quitting on me! Also, of course, if my pre-orders don't just show up at once like they have!
This is where you can see the 4x4 addition I added.
This was my previous layout, which started as a 2 train 4x8. It grew with another small 4x4 bump out.
That 4x8 above grew with another 4x4 bump out.
In between the current layout and the old layout above, I built some temporary 4x8s below. I couldn't decide what I wanted to do so these layouts only lasted a few months at most.