LWD 5.3" barrel. Wearing IWB I barely notice the extra length, but feel comforted knowing I am getting more velocity out of the 40.
What do you guys think? Would you rock this?
No. I wouldn't carry such a modified G27.
Once you start modifying firearms from stock condition, you get away from how the firearm was designed and exhaustively tested for normal functioning & operation during R&D and subsequent manufacturing.
Then, there's the potential risk of such modification becoming a potential disadvantage during any criminal and/or civil legal proceeding following a shooting incident.
Bear in mind that the .40 S&W was originally designed to use an old-style cup & core JHP fired from a 4" barrel (S&W M4006).
We have the advantage of a wider range of improved ammunition choices available nowadays, and the loss of approx half an inch of barrel length (4" M4006/4006TSW or 4.01" G23), or even an inch of barrel length (4.48" G22) wouldn't keep me awake at night.
FWIW, I own, use & carry .40 S&W pistols with 4.1", 3.46" (G27) & 3.5" barrels, and I've used the same ammunition in all of them. It's varied from time to time, especially depending on whatever's being issued at the moment, or authorized for personal purchase.