My first camera, about 35 years ago was a Rolleiflex Automat II. 120 film soon got too expensive for an 8-year old kid, so it was supplemented with a Pentax SV with the Super Takumar 50/1,4. Then came a Spotmatic, an Auto Takumar 35 and a Super Takumar 135/3,5.
In the mid 80's Minoltas were cheap and easy to find, so I got MD 21, 24, 28, 35, 58, 85, 135 and 200 lenses and some SR-7 and SRT bodies loaded with Ilford Pan-F, FP-4 and HP-5. When the silk lines for the meter coupling broke in the SRT-s it was cheaper to replace them with XG, XH and XK bodies.
Then I saw some slides made with the 35/2 Canon FD (new) and they blew me away with their nice bokeh, so I bought some Canon glass and a couple of A-1 bodies with Motor A.
When I was about 20 I worked as an assistant to a studio photographer who used Nikons, so I learned how to use the 105/2,5, the 105/1,8 and the 105 Micro-nikkor, and of course the 35/1,4. Then my own bag held an F2 Photomic and a Nikkormat with 24, 35, 50, 105 and 180 mostly pre-AI lenses. In the mid 90's I could afford 2 F4E bodies and had some of my lenses AI'd and upgraded some to AF versions.
In november 2001 I entered the digital era with a Kodak DCS 760 and a couple of Micro-drives. The 760 was slow, cumbersome and I had to carry about 2 kg of batteries for a day's work, but the colours at base ISO (80) were magnificient.
December 2007 came, and some assignments where I needed more than 1.5 fps and had to do digital for speed of turnaround, so time for a new body. The funds weren't there for a D3, so I got a D300 that I still use.
April 2009 saw the arrival of my D700, which is still my main camera. It is nice to have a 35 act like a 35 again, and not like a normal with too big DOF.
For me, the body is mostly a light-tight box with a lens, a finder. a shutter and some kind of recording medium but, and it is a big but, the ergonomics and controls have to help and not hinder what I want to do. My jumping between brands have been driven by availability and glass, rather than the latest and newest technologies.