So I came into this thread pretty annoyed. I don't ride a TSI, but all this ULTRA PRO IS LIGHTER, and the fact that you said that the "TSI IOS HEAVAYY" made me a little mad. Don't buy a scooter because its lighter. I ride a reinforced pro, which is heavier than the tsi (I think?), and so far, my scooter has lasted me 10 months and holdin up great compared to 2 months. I'd understand if the tsi and ultra pro are near equal in strength, but the truth is the ultra pro is just a cheap deck that will break in some manner thats one piece and very solid. Don't buy the ultra pro because newbs say its the best, or its light, buy it because its a solid cheap deck. The ultra pro and tsi really have nothing to compare to each other except that they are indeed both one piece, but are way out of each others lead.
Buy a certain deck for certain reasons. They vary. I don't ride either so I don't already have a formed bias opinion... tsi or ultra pro, but id recommend the ultra pro just because its a nice starter one piece deck thats cheap and easy. Buy the Tsi when you know your serious, and care about durability.