I have had very good experience with Wear Check. You might want to read some of their articles they have on their website to. They have some very informative articles that cover how to set up a good UOA program and what the results mean. http://www.wearcheck.com/literature/ Just click on the technical documents link for a full list of their articles.
Extending drain intervals is one great advantage of having a good UOA program. It can help to cut maintenance cost along with extending equipment life. Don't go overboard with extending drain intervals at the start. I do it in 15-20% steps. For example, if you currently do a oil change at 1000 hours on a piece of equipment you would do your first UOA at 1000 hours. If it comes back ok, go to 1200 hours and resample. Keep extending by 15-20% until you reach the limit and then set your drain interval at one step lower.
Example:
1000 hour test First test, OK
1200 hour test test, OK
1400 hour test test, OK
etc...
2200 hour test test, OK
2400 hour test test, shows fluid should be changed.
In this example I would run the oil changes to 2000 or 2200 hours. Continue to take samples at set times through the oil's life though to check for failure indicators. The price of doing 5 or 10 UOA's over a fluids life to check for failure indicators is cheap if compared to the cost of changing out large quantities of fluid and in preventing failures.
If you are using a high quality lubricant manufacturer you may find you get UOA's for free with the product. Check with your supplier.