Disclaimer: I am not a doctor and I did not stay at a Holiday Inn Express last night. I don't call Tirz and Reta weight loss drugs, I call them metabolic drugs.
I've done both Reta and Tirz (max dose of 1.5mg/week individually). For me, Tirz has more appetite suppression, but Reta is moving the needle slightly further on the blood tests I really, really care about (A1C, Cholesterol, HDL cholesterol, LDL cholesterol, Triglycerides). Both have lowered my subcutaneous fat, visceral fat, and blood pressure. I'm down to my maintenance dose of 1mg/week and am considering 0.5mg/week. I love them both. They're awesome!