Well, I agree everyone should practice slow flight but there are still problems at the slower speed.  In a Legacy, at 90 kts., even with full flaps, the nose is high and there is restricted forward visability.  Not the right configuration if you are trying as best you can to spot and avoid other airplanes and trying to figure out a complex arrival pattern.  Best case, you are likely to go low just to keep the rest of the traffic in sight.  At less than 90 kts., it quckly becomes marginal and, as noted, there is no way to be confident that 90 kts. will be maintained.  I have not gone into OSH but I did go into Arlington at 90 kts. (mercifully behind a string of 172s that actually flew the procedure.)  If I go to OSH, it will be in the high pattern.






"Go practice slow flight - everybody flying to OSH should.........
 
Even though the MAX/MIN speed limit is 135 Kts (or 90), remember that some idiots think that they should fly at their slowest speed possible, so be prepared to fly behind them.  I have gone behind (for a while) a Piper Cub that thought 65 Kts was just fine and, at the higher altitude, behind two twins that were hanging on Vmc"