I like ease of TrueRTA, but it hasn't had a feature enhancement in over a decade and is now seemingly limited compared to other packages out there. It appears the TrueRTA team is behind the Dayton Audio DAT5 speaker electrical measurement package, which is excellent, but not useful for acoustic measurements.
REW is shockingly complete and once mastered is very capable. It isn't perfect and doesn't give 100% consistent results as it relies on the OS for all audio adjustment, but if you learn to calibrate it works great.
If you don't have a mic, preamp and audio interface, I recommend the Dayton Audio Omnimic. It, too, has a learning curve, but it is outstanding for an all in one solution.
Finally, for spot measurements to make adjustments, Dayton Audio makes a calibrated mic for your smartphone and there are dozens of very good live audio analyzer apps out there which are free.