I was fortunately enough to start in the Cobra, and it remains my routine ship of choice. I've always added more ships than sold & bought. My signature shows the current roster - the T7 was added this morning, and along with the Asp requires fitout. The others are substantially complete, mostly 'grade A'.
I came to the Eagle and Viper late, due to a graphics problem (recently fixed) that made them (and some other ships) unplayable. My main issue with both (compared to the Cobra) is the primary hardpoints are under the body, whereas on the Cobra they are on top. I.e. the Cobra's class 2 points are on top, the Vipers C2 underneath, and the paired C1 points on the Eagle also underneath.
Why does this matter? I usually have gimbal pulse lasers and in the Eagle/Viper need to fly slightly "nose up" to get a target lock, and also have to keep the target ship below the centre of the windshield, whereas I've got greater visibility in the upper half of the screen, hence preferring the Cobra.
To be fair, I've only pootled around in the Eagle and Viper a couple of times. Anyone with more experience got some combat tips please?