It's a tough decision picking what you trust. I have a dozen Acur-Rites and some are usually within 2 points of each other for both temp and humidity.
I have four temp guns that cost in the range from $20- 60. They are within 3-4 degrees of each other as well as the Acur-Rites. Based on this, it can be confusing. I just try to make sure that there are no extreme variances.
I rely on the temp guns for surface temps and the gauges for air measurements as Coluber42 pointed out.