I have taken similar steps to those mentioned above. 35 mm, 6x4.5, 6x7, 4x5, 8x10. I feel that I learned a lot with the 4x5, but find myself wanting to shoot more 8x10. I have an Agfa/Ansco that I got from Midwest Photo.
If you have the opportunity to check out other people's gear, do so. I never had that chance. I am going to start doing some alt-process printing in the near future and that's why I decided to get the 8x10.
I am very new to large format photography and most of my work until recently has been on Hasselblad. However, I became interested in macro work and dug out my old 35mm system. I don't see the point of photographing something less than 36mm long on anything larger than 35mm. So I think it's down to fitness for purpose. My 35mm. landscape shots are fine, equipment easily carried, very convenient etc., but my Hass. pics. are very,very nice but the gear is not quite as transportable, and L/F, well you need a pack-horse and a lot more time, but the pics. are very, very, very nice. I now use 35mm, 6x6, and 5x4 depending on subject choice. You don't see L/F at sports events these days so I think it's down to the type of photographs you take and the sort of photographer you are. I'll stop now, people will be getting bored....
Big fleas have little fleas upon their backs to bite 'em, and little fleas have smaller fleas and so ad infinitum.
PS. It's not the equipment that matters, it's the end result!
Large format is for those things that give you time. Landscapes, portraits - anything not moving much. I regularly backpack with my 4x5. What I will shoot there lends itself to that format very well. If the subject would look best on AZO or as a Kalitype and would be good as an 8x10 print, I will use my 8x10 camera. I really enjoy 8x10. I don't have an 8x10 enlarger and I love the detail and sharpness of the contact prints I make with it. Portraits and landscapes - things that do not require much hiking or movement.
Now for the other part of the story. A good fast handling lightweight medium format camera will get you those steet shots and spontaneous shots that you will not have time to get with a 4x5. Smaller and lighter will fit fine with you anyplace you go. An equal amount of my photographic time is spent with a cheap used Bronica and a monopod. With careful shooting and good film and developer choice, I can make photos that will hang proudly on the wall next to shots taken with the 4x5. I make my camera choice based on this: shots that will be no larger than 4x6 - 35mm camera - point and shoot - Canon Rebel. For anything really worth taking a photo of but I can't set up for it - The Bronica ETRS. For shooting where I can set up - The 8x10 if I can drive there or the 4x5 or Rollei SL66 if I walk there or need to enlarge it.