How long have you owned the vehicle? Was the gauge not displaying the warmer temps in the past?
I don't think 3/4 gauges is out of the question in some circumstances, like high ambient temps, in traffic and with A/C running.
Unfortunately, without information about when the temp hits that mark I can't tell you if it's reason for concern or not.
One thing you haven't mentioned is the clutch fan and/or if it's in fair condition or junk.
If you get really nervous (which I did when I bought mine), get the UltraGauge. It's cheap and displays in numbers the coolant temperature. 210 degrees it not at all unusual in the scenario I listed above.
In traffic/around town, until the temp gets that hot I can't hear the fan howl. Indicating to me that it's finally reached 'hot' where the fan needs to start working appropriately.
The thermostat is a 196 degree I believe, and that is right about mid gauge on your 2008.
I can't really compare mine against yours right now...I think my thermostat has been hanging open for a while and never reached that temp anymore. It used to be pretty solid while driving at 188 then would creep up to 196 when I was not on the highway. Now I don't reach 180, or just flirt with 180. It only barely got to 190 a few weeks ago while climbing very long grades.
Please share more info about your experiences and why you did the work you have done thus far.
Other than the high temperature, is the engine operating normally? As 08Canyon mentioned, you have about replaced everything except the fan clutch. Does the temperature indicator needle return to "0" each time the ignition is turned off?
owned vehicle for 5 years never went past the middle mark clutch fan is working properly the top hose to radiator is hot and the bottom hose feels much cooler then the top hose. this is the second thermostat i replaced thinking the first one was bad . Never had two bad thermostats from the auto parts store I'm confused some