My fellow photography enthusiasts, I need some advice--actually I need a lot of advice. 
I have the Tamron 70-200mm f/2.8 and I've always found it be a pretty decent lens for the money. But I'm considering an upgrade to the Sony 70-200G. I shoot mostly sports--basketball, soccer, equestrian, and track. While the Tamron is a solid lens, I'm frustrated by how slow the focus is without the SSM motor.
However, the Sony is significantly more than what I paid for the Tamron. So, before I make such a monumental decision, I thought I'd toss it out there to my fellow Sony lovers.
1. If you have the SAL-70200G do you love it? Is it worth the rather hefty price tag?
2. If you've sold a lens through eBay, were you happy with the experience? If I upgrade I'll sell my old one, but I'm not sure if I want to trade it in or sell it on my own. Dodd Camera and B and H have offered me a trade-in value of $300.00 on my Tamron (pending inspection). Adorama has said that they "may" give up to $500.00 (pending inspection), but I'm wondering if that isn't a little bit of a lead on to get me to send my lens in and buy the new one.
3. Do you use filters on your lenses? I have always put filters on my lenses but I recently enrolled in NYIP and they are very much against the use of filters for protection. However, I'm slowly upgrading the quality of my lenses and it gives me a lot of heartburn to not protect them as much as possible. What are your thoughts on the subject?
My apologies if I have rambled on.

I have the Tamron 70-200mm f/2.8 and I've always found it be a pretty decent lens for the money. But I'm considering an upgrade to the Sony 70-200G. I shoot mostly sports--basketball, soccer, equestrian, and track. While the Tamron is a solid lens, I'm frustrated by how slow the focus is without the SSM motor.
However, the Sony is significantly more than what I paid for the Tamron. So, before I make such a monumental decision, I thought I'd toss it out there to my fellow Sony lovers.

1. If you have the SAL-70200G do you love it? Is it worth the rather hefty price tag?
2. If you've sold a lens through eBay, were you happy with the experience? If I upgrade I'll sell my old one, but I'm not sure if I want to trade it in or sell it on my own. Dodd Camera and B and H have offered me a trade-in value of $300.00 on my Tamron (pending inspection). Adorama has said that they "may" give up to $500.00 (pending inspection), but I'm wondering if that isn't a little bit of a lead on to get me to send my lens in and buy the new one.
3. Do you use filters on your lenses? I have always put filters on my lenses but I recently enrolled in NYIP and they are very much against the use of filters for protection. However, I'm slowly upgrading the quality of my lenses and it gives me a lot of heartburn to not protect them as much as possible. What are your thoughts on the subject?
My apologies if I have rambled on.