I was using a 3GS. I watched the live stream of WWDC, and Jobs announced the iPhone 4. I actually was quite determine to get the iPhone 4 as my next phone then. My contract, however, wasn't up yet so I had to hold on for a little longer. Along the few months of waiting, I was exposed to more and more news of WP7. I remember it being very iconic, the live tiles and stuff. Most reviewers on YouTube will be using the LG/Samsung WP7 device (not for sale).
Then, the first WP devices came onto the market. HTC, Samsung, LG etc. I was attracted to the HD7 for its big screen. I went with the HD7, and I liked it at first. After a long period of usage, I agree that the WP during that time is lacking. I was already considering an iPhone (4s/5) for my next device when my contract is up. Some issues that I faced with my HD7 was the ****ty LCD screen that is completely useless under sunlight, ****ty audio from the video recording, ****ty low light camera performance. The framerate of video capture was barely 25FPS I think.
However, I did love the lenses that you can use with the camera. The app selection was a joke, but I really dig the "Metro UI". I liked having the big headers that made WP iconic. Don't really like how the current mainstream apps are like their iOS or Android counterparts. Twitter would be a good example. The old design was really different and I prefer that design language. I like the social integrations. I like how fluid the OS is.
Then, Nokia came into the picture. Elop showed the "Searay", and I immediately regretted my HD7. Along the year, more and more devices were released. I remember wanting to get a Lumia 900 badly.
Microsoft announced WP8. I like it very much, but I had a hard time accepting the fact that they removed the "gutter" on the homescreen. I feel that it was something that made WP unique and different. It made the homescreen too symmetrical, and that's why I am currently looking forward to WP8.1. Wide tiles will be awesome on the homescreen

Watched the Nokia event and Elop announced the WP8 line up. Decided 920 will be my next.
About 16 months with my 920 now. I'm already wanting a 1520, like how I used to want a 900.