Walther PDP Compact 9mm vs Walther PDP Full Size 9mm

Same pistol in two frame sizes, at the same $699.00 MSRP, with the same 1.34" width, optic cut, Performance Duty Trigger and two magazines. The Walther PDP Full Size 9mm adds three rounds (18 vs 15), a 0.5" longer barrel (4.5" vs 4.0") and 0.5" more sight radius (6.9" vs 6.4"), at 8.0" overall against 7.5". It is also 0.4 oz lighter as listed (24.0 oz vs 24.4 oz), and its trigger is listed at the same 5.6 lb.

Pick the Walther PDP Compact if:

• A 7.5" overall length suits your holster and your frame
• Fifteen rounds is enough and you would rather carry the shorter gun

Pick the Walther PDP Full Size if:

• You want 18 rounds instead of 15
• The 4.5" barrel and 6.9" sight radius help you shoot it better at distance
• You want the longer gun with no weight penalty — 24.0 oz against 24.4 oz

Since price, width and features are identical, this is purely length and capacity against concealability. If the gun lives in a range bag or on a duty belt, the full size costs you nothing; if it goes under a shirt, the 0.5" of length is the whole argument.