nate7520 said:
Also, if you are just learning, being stuck with a low fps camera will teach you how to capture the moment rather than just motor driving.
This is a good point as well. No offense intended but as cameras get better and better, I think photographers get worse and worse. I don't mean this happens on purpose or necc results in bad images, I just mean that the photographer is robbed of the crucial experience of having to think harder and develop good habits and techniques that are required when the equipment can't compensate. We all rise to the level required of us and much less is required if the equipment lowers the bar. When the going gets tough, sometimes good technique and experience is what saves us.
For instance, I think all DSLR photographers that have never shot with older manual film cameras that only had a basic light meter in them to help set the manual settings have missed out on some great experience. Now these days, shooting with an older DSLR like a 30D, 40D or 5DClassic will still force someone to develop better skills to overcome the sensor limits, esp in low light.
I am guessing that the OP has likely learned a lot using a T3i and a slow lens to shoot indoor sports. He will no doubt appreciate the new technology of the 70D or 7D2 after having shot images with the older tech.