We started with an ez steer on tilt on 7250, then went to an On-Trac II. problem was dad was getting older and the resistance to get the on-trac to release and steer on ends was hard, tried to recalibrate things but if we set it lighter the on-trac would kick itself off if it had to steer too hard. Got rid of the 7250 then and moved to a 315 with integrated..problem solved there. moved the on-trac to the 5488 for planting and same issue seemed like we had to fight it sometimes to get it to release, or if set too light would kick itself off on its own. Got tired of that and put an integrated hydraulic system on 5488. Its been problem free for several years now.
I'm not too far away and would be happy to show you what we have done if you want to take a look. It is more money for the system and the upgrade to a 750 or higher from your 500. The other systems can work with the tilt wheel, just have to get it mounted up right.
Happy to help if you have questions...