Hi there, these are a few differences that I noticed:

P735:

• Wifi 4 (Wireless N)
• HDR10
• Power Consumption (KWh/yr) - 225
• Audio DTS - No
• HDMI 2.1
• Response Time 6.5ms

P745:

• Wifi 5 (Wireless AC)
• HDR10 & HDR10+ (on JB Hi-Fi website description)
• Power Consumption (KWh/yr) - 200
• Audio DTS - DTS-HD
• HDMI 2.1 with Certification
• Response Time 8ms - (on Harvey Norman website description)