I asked same question once here and got mixed results. I did some research before I bought mine CCM Vector ZG130 (which I'm pretty happy with). Most T-blade haters never bother to figure out what is that they need, skated on first blade and condemned it because it was different. If you take time and pick up suitable blade, you'll be just fine.
T-blade system allow you to experiment with different rocker and hollow curves on your runner. In other words, you could customize your skates. You may need to go through 2 to 5 different shapes before you get one you like.
I suggest to start with the T-blade that close replicate the skate you are skating now. To do so yo need to know 1) your rocker 2) your sharpening hollow radius 3) your boot size. I suppose everyone knows the boot size. In case you know ONLY that, if your skates are CCM, you rocker radius would be 11 ft. Bauer use smaller rocker - 9 ft. The hollow radius is next. The smaller the hollow radius, the more "bite" you get. some people just hate when skates "bite" too much. They scratch the ice diligently after each sharpening before starting skating, while all they needed to do is ask the guy who sharpens the skates to retool the machine for larger hollow radius. Most pro shops use 1/4" or 5/8" hollow when you get you skates sharpened. I like mine at 3/16" or at 3/4" (hate when they "bite").
Getting done all the home work I recieved the skates that were very close to what I used to plus I got Vector boot which is by far superior to TACKS one I had before.
Only after I broke my new Vectors in I started to experiment with different runners. I did not depart much from what I had before - just one size smaller rocker ( My order came with 11') and 3/4" hollow radius (I got 3/16"). But it took me through 2 runners because you cannot change more then one parameter at the time to understand the difference. Each blade cost $15. So including shipping I ended up spending $40 more. As a result I have the skates that are impeccable.
T-blade system, IMO is like two piece stick that alows you to use different blade curves. Some players never bother to try different blade and doing just fine. It is up to you.