I don't have any experience with the Outback, so I can not answer any our your direct questions.  I guess I am going to get on my soap box here.

Currently on a few top end systems have the capabilities to do all that you want to do.  Everybody wants a cheap auto steer system, but too many people are rushing out to buy systems that do not really meet their needs.  There are certainly places and applications for the less expensive systems, but many farmers are going to be disappointed in them.

I am going to give some general guidelines for a system and they are only MY OPINION.

• For row crop work, I would not consider a system that can not save the lines for a field and recall them the next time you return to that field.  I am not necessarily talking about having repeatable accuracy.  I am talking about having the lines set so you do not have to reset them the next time you run the field.
• Going along with the first bullet, I would consider the capability of having multiple lines per field an absolute requirement.
• Signal accuracy -- There are multiple level of correction signals for a reason.  They have different levels of accuracy and contrary to the claims of some, you do get what you pay for.  I have said before and I will still contend that WAAS is not accurate enough for row crop work.  I know that many are planting with WAAS an they report that they are happy with the results.  Some of these reports come from people whom I have high respect for.  But planting is only one operation.  You can not come back and spray or side dress using the WAAS signal it does not have the repeatability to do this.  I can not justify the cost of an auto steer system just for the planting operation.  There is a lot of bang for the buck in the cost to move on up to one of the higher accuracy satellite correction signals such as OmniStar HP or SF2.  With some nudging, you can get a reasonable degree of repeatability.  Even if you plant with WAAS, you are still dependent upon markers to know when and how much to nudge.  When purchasing an autosteer system, I think you need to purchase a system that will let you get as much use as possible from the system.  AGAIN, THIS IS ONLY MY OPINION.  IGNORE IT IF YOU DO NOT AGREE.
• Electric steering wheel control vs. hydraulic valve interfaces.  The best systems are the track tractors that tie directly into the CAN system.  These system are very easy to calibrate/tune and do a very good job.  The electric steering wheel motors do a good job at lower speeds and work very well on some vehicles.  As ground speed increases, the hydraulic interfaces are generally superior.
• Tilt compensation -- I would not consider an assisted steering system that did not have tilt compensation.  You can get by with out it in some situations on extremely flat ground but even a little cab bouncing will greatly affect the accuracy of the system.  As ground speeds increase this becomes even more important.  And there are very big differences in the accuracy of the tilt "compensators" that are on the market.  Again, you get what you pay for.  But, you may not need the accuracy of the top end systems either.
• The first thing you need to consider when choosing a system is what your needs actually are.  If all you are doing is broad acre spraying and fertilizer applications, then a low end system using the WAAS signal with a low level (or no) tilt compensation will do the job more than adequately.  I would still consider the capability of saving the field lines necessary.  What if you have to leave the field and come back later to complete the operation?  If you are going to do repeated field operations and need any level of repeatability then the low end systems are going to leave you disappointed.
• When you look at systems, don't just look at your needs today.  Consider what you will want from the system a year or two down the road and then look at the upgradability and capabilities of the system.  Will you want to add rate control or VRT capabilities?  Will you want higher levels of accuracy?  Will the ground speed of your operations increase?  Will you need to transfer guidelines to other vehicles or other guidance systems?  What are the data logging capabilities?  Buying a little more to start with can save you money down the road.
• Be very careful when buying new systems on the market.  Most companies are very good at advertising features that are not quite perfected yet or in some cases aren't even available yet.  And many times it turns out to be expensive to add those features later.  More and more, companies are releasing systems that are not fully debugged yet.  We are doing the field testing and debugging for them.  Some are very slow to respond to firmware problems and hardware bugs. 
• Look very hard at local dealer support.  In most cases this is where your support will come from.  Very few companies are offering direct customer support.  They are expecting the local dealer to handle all support questions and support issues.  There are some excellent local dealers out there.  But many dealers do not handle these systems on a daily basis.  Many have little if any seat time with the units.  Many times you will find that your knowledge of the system exceeds the knowledge of your dealer.  Support documentation varies greatly with different systems and documentation is usually several months behind firmware and hardware changes.

We are starting to reach the market phase of "mass adoption" on autosteer.  Many people are rushing out to buy a system and some are making purchase decisions based on cost alone.  That is a BIG MISTAKE IN MY OPINION.  Do your home work first.