I think Mike990 hit the nail .. more or less... you can argue the addage "when my life is on the line.....i want the best" but, I happen to be friends with Some officers that are on local SWAT, CERT and even the Crisis Response Teams for the up and comming Olympics and as far as knives go... almost all that carry, are carying folders of substantial quality and history (no plugs this time... ) the reasoning; if there is a hostage situation, and an officer becomes involved most likely, the firearms are going to be taken away or rendered usless (no ammo) so the knife is a last ditch effort for the "never take me alive" mentality, or at the very least cutting restraints a hostagetaker might use... obviously a large Strider, Mad Dog or even a Buck would be easily found and removed. So the sturdy folders hide very well in the "tac-gear". I even clip a back up spyderco inside my pants to my boxers.. as that last/worst case tool .. and never even know its there.
If hard cutting is an issue... a quality serated blade cant be beat. I dont think you need 9" of 1/4" differentially tempered stock to saw through seatbelts, harnesses, ropes, even basic wires...
As far as an entry tool.. An entry devise such as a Door Ram or a fireman's Entry bar would get you in anthing in seconds.. where as even a 10" blade would take you a while .. Ive never heard of any organised team having to resort to a knife as an actual entry tool, except during 'camp fire chat' and "i was there" storys...least the topic of discussion being war where a Spec Ops soldier had to do the most with the least.
Again.. before anyone here can advise any tool for the job.. we'd need to know what job your "tac team" is trying to acomplish. If your with the DEA or a SF Operational Detatchment down in Central America fighting the coke lords your going to need a different tool than if your part of the Eco Challenge, or even a rural SWAT/CERT team..
I have met some of the guys from TOP's and Mike Fuller is one hell of a guy.. I personally perfer their smaller knives as packing, camping, and general fighting concepts than I do their large "tacticle" knives.. sometimes simple is better, and there is no place that seems to be more true than not in survival situations.