Hi Chittaway,
This is a question we have been considering ourselves (being of a similar age). There seems to be so much uncertainty with how long the 173/143 visa process with take in the next few years. We had been hoping for a 2-year queue. But if this stretches to +4 years, the aged visa may be a better option. We would really need to know how many are currently queuing, to be able to do the maths.
So our own plan is to stick with our 173 application for now, and to re–assess our situation over the next 2 years.
I feel, reading back though this thread, dealing with the uncertainty of this process is causing the most stress. I have the greatest admiration for everyone who has sold-up and shipped-out pre-visa grant. But I fear, all of us at the back of the queue, may have to accept a +4 year wait as the new norm.