Was there a performance problem with your current shock that your trying to fix with the Push upgrade, or is it classic upgradeitus?
A custom tune is a custom tune, and a Push custom tune is only an ugrade on a custom tune if the Push gubbins is actually doing something inside the shock which is of benefit. From what I remember of the two Push upgrades I’ve had the reason for TFT reccomending them is that because of the particular issues I was having with “packing down” on repetative hits the Push system allows more oil to flow and improves this aspect of the shocks performance.
A custom tune improves what you think is wrong with the shock if you give the tuner the right information/feedback. Buy a new shock and your starting from baseline settings, which may or may not suit you… which is the right thing to do?
So… how do you think the performance of your old shock could be improved? Will a new shock with it’s bells and whistles do this or would tuning the old one be better?
Edit – reread the first post. It’s a 2005 shock so 7 years old, and it’s a 165 eye to eye so probably on a shorter travel type bike. Shock sophistication may not give huge benefits in this type of application (IMHO etc etc) so get a standard service (or custom tune if you think it’s worth it) but if the tuner tells you the shock is tired by a new one.