The real question is, are you flying in Open Play or Solo?
If you're in Open, a T9 is literally a flying pinata waiting to be popped. My T9 has been interdicted at least five times during my brief 2-week airtime, got shot down twice, managed to destroy the pirating Cmdr twice, though the damage caused to my T9 is about as much as the profit of an hour's trade. Not the best way to make money unless you can find a rather low profile trading route.
Anaconda, on the other hand, doesn't have much to worry about pirates. For obvious reasons.
It also has a much better jump range, much less fuel consumption, and much better agility (for a massive ship) in both normal flight and supercruise. You can also outfit an Anaconda for battle. Yes, a basic Anaconda cost about twice as much as a T9 and has less cargo hold, but you don't have nearly as much things to worry about.
If you're flying in solo, however, T9 all the way. A T9 could easily squash any NPC the game throws at you up to Asp, and with some practice I've managed to defeat Fed Dropship and Emp Clippers with it too.
