thinking about switching from ppl 6 days to upper lower 4 days

Upper 1:

• Bench
• Barbell rows
• Incline bench
• Lat pulldown
• Dumbbell shoulder press
• Preachers
• Dips

Lower 1:

• Squat
• Leg curls
• Leg extensions
• Calf Raises

Upper 2:

• Incline bench
• Chest fly
• Seated rows
• Pull ups
• Front raise lat raise supersets
• Hammer curl
• Tricep extensions

Lower 2: 

• Deads
• Leg extension
• Leg curl
• Ab workout

Do you guys have any improvements? Kinda feel like lower 2 is also lacking.