I have been very happy with JD over the years and my wife grew up with them so we remain green. That said, the other major makers do make great tractors also...you just tend to stick with what has never failed you. I know darn few who have ever been upset with their orange tractors also. I have other equipment/attachments from Long, New Holland, Landpride, Befco, etc and have been happy with them too. One reason I have stuck with JD is that they have a bit more USA made are increasing that percentage. Also, during the depression they were the only major manufacturer that did not reposes their equipment. Their view at the time was that if they are still able to stay in business then America needs it's equipment more than they need every red cent. I can't 100% confirm this but have found it in many historical sources...I think it is true. Now their numbering system is crazy...
The numbering system is consistent within a range and year...after that all bets are off! Happily the new 50XX series do match the "XX" with the horsepower...WOW isn't that a novel ideere!--Maybe they should confuse us more and call their new numbering system "I-Match?!" So they may be leaning toward more consistency. Also, generally the bigger the number the "bigger" the tractor. I agree that the quality genrally does not rise so much as available features.
Your confusion is shared by all. Tractordata is a great web resource.
Peter