Now for the record I have the Daytona 675, not the St. Triple, a Sport 1000 and used to have an S2R800. Maybe I can throw a little insight into this.
The 675 is born from a RACE bike.
First off, the above statement is incorrect. Triumph had no intentions of racing when they initially developed the 675 engine. They already knew that it would not be allowed to compete in any class, not even in the UK, at the time of its inception. Yes it was initially designed to go into a Super-Sport sort of bike, but race bike it is not. Granted that this has changed since the bike/engine was first designed...
Between the 696 and 675...its realy hard to not pick the street triple. But that bike is in a whole other class of its own. Its a straight up hooligan machine. the 696 has a like 8 inches or a foot on the Street triple. That thing is a make the beast with two backsing wheelie MACHINE!!!
This is very true. The Striple, much like its big brother, is a complete hooligan! The motor was "detuned" from the Daytona, and while it did lose some of the top end power it increased the mid range punch, and if you have ridden the Daytona you will know that is saying a lot.
Listening to the triple is kind of disappointing. It sounds like it's wheezing and underpowered at lower speeds.
Not when ridden in full tilt mode. The triple is a very different sounding powerplant, with its gear driven counterbalancer, but it really screams when you get the revs up.
The exhaust on the 696 is much more interesting and sexy. When you get on the throttle, it sounds like your going to run people over and take their lunch money, even more so with a set of Termis on it. The triple more or less asks you if he can borrow a couple bucks and he'll pay you back tomorrow. Check them both out if you can, you won't be really disappointed by either one.
Keep in mind that while the 696 has the Termi kit to make it sound its best, Triumph has the same sort of thing with Arrow. They are MUCH cheaper (you can get a full Ti system for the Triumph for the cost of the 696's slip ons) and you get better performance gains as well.
The Ducs slipper clutch is also a plus for the novice rider. It may save your ass if you drop a gear mid corner.
The 675s do not really have anywhere near as much engine braking as you might think, and because of this a slipper clutch isn't as critical as it is on the Ducati. I have banged my way through the gears around many turns on the Daytona and the only time I ever came close to having a wheel hop problem was when I put it into first in a right-handed bend at high revs. My old S2R had a much bigger problem with wheel hop, even with it's "slipper" clutch.
One other thing to keep in mind; while many people have had issues with the fuel mapping/ecu set up on their 696s, and have almost always had to put either an O2 emulator or the DP chip in to rectify, the Triumph comes factory loaded with three maps store in it's ecu. One map for the stock system, one for slip ons and the third for the full (cat-less) exhaust. All it takes is the dealers laptop (with Triumph diagnostic software) to change between the three. And if you have a good relationship with your dealer you can probably get that done at little or no cost.