http://www.cruisecooler.com/Cooling%20Tech.html
Here's an interesting piece to read.

At last I can shed some light on the matter, still weird but very acceptable.

Hooked up the Temp Gauge last night and had it idling in the garage to test the system and the new fan switch before taking it for a drive.

On Idle Temp was running at a maximum of 75 degrees before the fan kicked in, fan is on for a short while and then switches off, at least I know the fan is more than sufficient to do the work.

When doing normal town driving at 60-80km/h, the temp is sitting between 68-72 degrees with robot stops included.

On the Highway it stays at the 68-72 degree range until you stop at a off ramp, then it climbs to about 75 degrees, after that it doesn't really come down on the highway, until you drive into town sections, within a kilometer it goes down to the 68-72 degree area. - Weird part, maybe heat soak, pressure, I'm clueless. But the temps is so low, it is not going to bother me anymore.

Lessons learned:
1. Stock Gauge and Temp sender is very good
2. If you need to replace the stock temp sender with a pirate one (Especially RSA) rather buy a new gauge and sender that reads degrees rather than just a low and high scale.
3. On installing a different radiator, install a new Gauge.

I highly recommend VDO gauges.

Thanks for all the help and suggestions.