Alot depends upon the particular use you plan to put the tractor to. The 6000 series is a damn nice tractor but it is a good bit larger in size. Will this larger size impede you productivity or enhance it? The 50-70 hp range sure does sound like prime territory for the 5000 Twenty Series to me. You can always go to the 05 and 03 Series to get less features and cut down on cost.
A 5220 MFWD equipped with the following:
12F/12R PowrReverser
Isolated Open Station Platform
Horizontal Side Exhaust
Standard R-1 tires
Dual Rear SCV with Lever Controls
Dual Mid SCV with Joystick Control
Rockshaft with Telescoping Draft Links
Is going to put you in the $27,000 price range and maybe $500 less if you can cut a really good deal. John Deere is offering some very enticing incentives as well. You can go the the John Deere & Kubota web sight and compare these tractors and see exactly what you are getting for the money spent. The 5220 above is a very nice package and comes with a LOT of goodies and more gears to choose from not that this is always such a big deal.
5220 Utility Tractor (53 hp)
Special Offers on John Deere Utility Tractors
More Special Offers for Ag Use
I looked a bit more and found you can get a 5205 MFWD (8F/4R SyncReverser™ transmission is standard equipment)equipped with the following:
Folding ROPS
16.9-28 In. 6PR R1 Bias rear tires
9.5-24 In. 6PR R1 Bias
Dual Rear SCV with Detented Float and Lever Controls
Dual Mid SCV with Joystick Control
Telescoping Draft Links
That would put you in the $22,500 to $23,500 price range with not quite as many bells and whistles.
5205 Tractor
Any way I hope this is not TMI. I wanted to put some ideas out there for you. If you want more hp; you can always step up to a 5320 or 5420, or even a 5520 if you want all 89 hp. The 03 series are pretty spartan but maybe that is what appeals to you. Nothing wront with simplicity! :thumbsup:
The best advice I can give you is if you haven't already; demo any of these tractors you may have an interest in to include the other color tractors and make an apple to apples comparison. If green is still what toots your horn (and it does mine!)

Go for it.
The 6000 series is getting into the large row crop sector of tractors and I am not sure that is what you are wanting. They are nice! :rockin: The key is which piece of equipment will meet your requirements at the best price and be reliable, as well as give you good service?