Which Tamron? There are two, the non-VC one (cheap and really quite poor) and the SP VC version (more expensive, very good).
I have a 7d and tamron 70-300vc. Haven't used them much recently but made good use of them last year.
It's a good combination and I got some (in my opinion) very good results, printed one off at A3+ for a friend to frame and hang in their dining room. The lens stabilisation system is very effective.
I've had a go with the non-VC 70-300 on a 7D and I was genuinely impressed with it for the money. I wasn't using it for anything serious, I just had a chance to pick one up for under £100 and wanted to see what that money would get you. Honestly, it's not a bad lens. In fact, I'd say for the money, it'd be hard to beat. I'm sure I have images from that lens with a 7D if you'd like.
I've had a go with the non-VC 70-300 on a 7D and I was genuinely impressed with it for the money. I wasn't using it for anything serious, I just had a chance to pick one up for under £100 and wanted to see what that money would get you. Honestly, it's not a bad lens. In fact, I'd say for the money, it'd be hard to beat. I'm sure I have images from that lens with a 7D if you'd like.