Bob Frein said:
Im in the small category…I have about 55 feet of track in phase 1. Sure, we have all dreamt of having a great empire in the back yard, but like Greg said, here in So Cal, LA particularly, we dont have a lot of real estate to work with.
I am building in 3 phases so A) I can keep within a budget and B) start running trains now until the next phase can be finished.
I think there are a lot of people that plan out a large railroad and never lay a piece of track because they are waiting to build it all at once…and then never build it and eventually sell off everything and get out of the hobby.
Life is too short to sit around dreaming and not running trains!!! 
I agree with you 100%. So many people want to build all at once and never get anything down. I did what you did. Started with about 50ft varied oval and add as I got money and track. Im up to around 150ft and thats my limit. I have no interest in going bigger, even though I have track and plenty of space. I prefer a manageable size layout. If its too big you spend more time maintaining then running
I think everyone will have their own interpretation. 500ft of track with sidings, landscaping, buildings, bridges will look much larger then 1000 ft of track with no landscaping etc… To me a landscaped layout up to 200 ft of track is small. Over 200ft is medium size and over 800 large.