I was all about speed and part of me still is. When I started to record songs, I realised most people hooked on the simplest of riffs, something they could hum easily.
When I find myself closing my eyes to visualise the guitarist play his solo, then I know he plays with feeling. I can play relatively fast (after 11 years I should lol) but I rarely use my speed when I work on songs. I keep my speed for GuitarWar, and showing off to shut up little cocky guitarist ;) you've stumble upon them too I'm sure.
In the end it's all about dynamics for me, a song with all blazing speed solo is a not a good song, the same goes for a song with mellow feeling solos. You must use dynamics to hook the listeners and variance to keep them.
The hardest thing is to have a good balance of both and when you do, you just know it.
Listen to A song for Rachelle by Greg Howe, it's the perfect exemple. Well for me at least.