are engine oil analysis worth doing? can they predict any issues or are they just snake oil?

something like this www.roktex.com.au/ where you send in a sample and they do some testing in a lab?

I believe they can be valuable, but not necessarily needed. The test will tell you if there is metal in the oil and what type of metal. Oil will have metal in it, even with a new engine, but the oil test will tell you whether it is normal or an indication of major wear and in which area the wear is.
As an engine wears it makes noises and if it is worn enough to fail an oil test you should be able to hear a problem. A good engine person can hear most problems such as bearing noises, piston slap etc as soon as they start. Use a big screwdriver held on the engine and with the other end against your ear as a stethoscope. Listen at idle, increasing and decreasing revs and under load. You should only hear wurring sounds, no knocks, slaps or rumbles.
Other symptoms such as poor starting, low power, low oil pressure also give pending major problems away.
If it is ok using these tests an oil test is, in my view, unnecessary.

thanks for the input guys..

hg02 has offered to send up a oil analysis set and get it done at his work .. again hg02 goes above and beyond.. top bloke

if only he would accept my home made moon shine in return for the favours but he doesn't seem to want to partake in the damage it may cause