The MP33 is a wonderful stick!! As the TW phenom was hitting the golf industry, everyone wanted to 'be like Tiger'. At that time, he was with Titleist and playing a set of Titty blades. Titleist brought out the 681 and the 681T line for the masses. These were good sticks, but were the last of the Hoffman forgings and had some chrome peeling issues. Soon after the 681 line hit the retailers, TW moved over to Nike. Titty moved their forging business overseas and replaced the 681 line with the 690mb and 690cb.
The Titty 681 line was selling well. TW's actual blades, when with Titty, were a combination of Mizzy MP14 and MP29 sticks that he had played for quite a few years. They were forged by Titty, but were almost exact copies of the Mizzy clubs. Not wanting to be left behind, Mizzy brought out the MP33. This iron surprised many by how easily it played. The MP33 was not the typical "blade" that left your hands stinging and shots way short of the target. They were a huge success!!!
I owned a couple sets of the MP33s. Ended up replacing them with some 690mb Titty blades. That was only due to some name loyalty for an acquaintance then pretty well tied to Titleist. There was never anything I asked of the MP33s that they would not do. Both of my sets had the DGS300 shafts. Both seemed to play well out of the box.
Enjoy! They'll be quite a change from your Slingshots. Once the eyes adjust, I don't think you'll ever look back.