The stock ball bearings are cheap. My schwin bike had better. Also mine were put in at an angle so I was cupping tires in 3,000 miles.
The alls balls bearing are direct replacments, no mods needed. Gives a lot firmer and more secure feel to the front end. IMHO
The job can be done with out the recomended tools, but I wouldn't want to try it. Best to find some one that has the tools and borrow them from him. There are a couple good write ups on the OA about doing this.
Jerry