I have had some dealings with AllBalls and it all has been good. They make a variety of products and they have helped me out of a few tricky situations from bearing issues for oddball applications to an electric starter on a Harley. I have always been impressed with their customer service.
They try when possible to source bearings from the US or Canada. Sometimes when a part becomes too expensive or too obscure to source from North America they will source from overseas, but they do their due diligence in checking on quality.
Keep in mind that they are not a bearing manufacturer, but a supplier that researches bearing availability from different manufacturers and applications then offers them for sale. There are very few actual bearing manufacturers and even the OEM's will usually try find an existing bearing when designing an assembly. The engineering and cost that goes into producing a bearing to spec is insane and if they actually had a bearing made to spec just for the RD the retail price would reflect that. Considering this, it is totally reasonable that the tapered bearing kit they offer for the RD steering conversion sits a little taller than the original ball bearings. Ball bearings have a very thin stacked height while tapered bearings of the same I.D. and O.D. are usually taller to allow enough contact surface for the bearings. Could someone have a bearing made that had the proper I.D., O.D., and stacked height? Yes, but it would be a custom bearing with very little usefulness outside of the RD steering bearings. Production numbers would be very low and the cost per bearing would be very high in order to pay for the cost of engineering, design, and tooling.
I have installed the All Balls steering kit and had no problem with it. It does spread the triple clamps a little further apart, but I simply put an o-ring over the gap. People on here have come up with similar solutions for the headlight ears. As to the seals, they don't have to be anything special. Steering bearings are a low speed bearing and the grease doesn't get flung around like in a tapered wheel bearing. The seal is simply a dust shield to keep contaminates out. Some bikes with tapered bearings don't even use a seal. They simply have a small thin metal plate covering the bearing to keep contaminates out.
To sum it up are all the All Balls kits a 100% perfect solution? No. They are not, but kudos to them for sifting through the commonly available bearings to find replacements at a reasonable price for all the various applications they offer. I have searched on my own through available bearings for weird applications and it can be a real time consuming headache. An oddball German manufactured trike that used a European Fiat wheel bearing comes to mind.
BTW....my only complaint about All Balls is the name. More than once I typed in www.AllBalls.com
click on this link!!!!) while searching for their website and wound up on an x rated site that was not my cup of tea. Use your imagination....
Their website is www.AllBallsRacing