Lens for wildlife

No when I bought my Sigma there was only the DG version available, I'm told that the APO is much better, which is also a consideration, depending how much I get for the DG version on E-Bay, I like the DG version , however I'm told the Apo version has better glass and is much more clear,if it had of been out at that time I would have bought it. Yes I'll use the Tamron mostly this weekend, this one deosn'r suffer purple fringing like some tamron do.
Paul

the sigma is suppose to be very good, but does get softer towards the 300mm, and thats about the only thing to worry about, and i dont mean to sound like i know it all, but the apo will be better, but at price of £150.
the tamron suffers from purple fringing this can be corrected easy via software, i do have the tamron and i love it, its a very sharp lens but it only cost me £50 delivered, also have you considered the
pentax 55-300mm at £190 delivered

Of course Pentax,never even crossed my mind,I'm lucky with my Tamron NO purple fringing so far,I was bought photoshop at Christmas, and I believe there is a way of getting rid of such things, not a probelm for me so fst thankfully, and youre not souding like a know it all, good advice stops some of us making huge expensive mistakes.
Paul

paul how old is the tamron, also i dont think you will get alot for sigma but on ebey who knows the last time i looked the tamron were going for like £90 used when you can buy them new for £100.
like i said i love the tamron 70-300mm, and also my 18-200mm dii aspherical tamron but even this suffers from purple fringing not as bad as the 70-300mm, but my sigma nothing at all,

also it the tamron autofocus or manual,

is it this one,
http://cgi.ebay.co.uk/TAMRON-200-400mm_W0QQitemZ220379103236QQcmdZViewItemQQptZU...

I wish mine was this compact it about twice the length of this one.

Manual,full opened it's around 13'ins lon and it was a M42 thread , with an K mount adapter now, perhaps I should keep the sigma DG as a spare

okay maybe thats the problem, i could not focus fast enough for birds, thank good for af, also what budget was you thinking,