This topic has been long debated over the years. I think that one of the thing to consider when chossing an IGP is the how comfortable your staff is with the protocol.
I personally prefer ISIS because it always seems to have the support for new address-families (IPv6) , features (multi-topology) and extensions (TE tunnel extensions) first. This is due to ISIS being more flexible when it comes to adding extensions.
Hope this helps,
Harold Ritter
Sr Technical Leader
CCIE 4168 (R&S, SP)
harold@cisco.com
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