Explain how or why anyone would need or want to swap frame sizes or calibres? If a compact Glock/HK/SIG does the job then there's no need for a full size gun and vise versa. The modularity thing was a retarded request by the US Army and far from a practical one. Regardless you can still swap calibres with a Glock by simply swapping slides and if you feel so inclined the trigger mechanism housing but it's not required.(applies to standard frame guns only)
The trigger is crap for a single action striker fired gun with a published pull weight of 5.5-7.5 lbs and tested models running at just over 6 lbs. And yes it is in fact a single action striker fired gun unlike the double action of a Glock.
https://www.youtube.com/watch?v=Y_qStEMQPts Start the video at 1:55 and watch the striker as it is RELEASED with the trigger pull and not charged and released.
Here's another write up about their striker design.
https://www.americanrifleman.org/articles/2015/4/23/clarifying-double-action-only-dao/
Here's my list of Glock pros, beside each line I will add a "G" for Glock or an "S" for SIG or a "B" for both guns.
Low bore axis
G
Cold hammer forged barrel
G
Polygonal rifling
G
No positive safety
B
Reliable
G (The 320 has very little track record)
Low profile controls(slide stop)
B(even though the location of the slide stop on the 320 is difficult to reach with your thumb as it's behind the first knuckle)
Fewest parts of any service calibre pistol
G
Interchangeable sights
B
Light weight
G
Slim/small dimensions
G
Consistent trigger pull
B (although the 320 trigger could be anywhere between 5.5-7.5 lbs)
Short trigger pull
S (by 1/10th of an inch and it is a single action gun. Sh*tty trigger for an SA gun)
100% drop safe
B
Parts interchangeability between same models and most other models
B
Magazine interchangeability between like calibre guns
G
Large magazine capacities(compared to overall dimensions and weight)
G (dimensionally the G is smaller and lighter than the SIG with equal capacity)
Multiple sizes (long slide, practical/tactical, full/standard, compact, sub compact)
B(more options for the G)
Identical control layout(all models) and size across multiple calibres/models
B
Easy to repair(one tool required)
B
Cheap to repair
B
Holster cross compatibility over multiple calibres and models
B
Ergonomic grip angle
G(sorry, the 1911 grip angle is wrong which is what the 320 is modeled after, a locked wrist is more stable and the Glock grip angle was designed around that)
Accessory rail(not on all generations)
B
The only attributes the SIG has are the shorter trigger which it should as it is an SA gun not a DA gun. The gain is minimal and the weight of trigger pull is brutal for an SA gun. And the "modularity" of which no one ever needs or wants it as a calibre or size convesion kit is almost the same price as another complete gun. What has SIG designed on their own that doesn't have it's roots in a Glock? The trigger tab safety is a Glock trait. The very low profile controls and lack of manual safety is a Glock trait. The Polymer framed striker fired pistol with the aforementioned attributes was popularized by Glock. In the early years everyone poo poo'd Glocks and said they were junk and that striker fired guns and especially polymer framed guns were a fad. The lack of a manual/positive safety was dangerous and another fad. And yet here we are, a world where everyone and their dog is trying to copy the Glock recipe and sell the same product.
Here's who has attempted to make a "better" poly striker gun.
FN(multiple times)
S&W (multiple times, even got sued for patent infringement once)
Ruger(multiple times)
Springfield(multiple times)
HK
Arsenal
Diamondback
Kahr Arms(multiple times)
SIG
Walther(multiple times)
Steyr
CZ
Beretta
Remington
Avidity Arms (Rob Pincus design)
Kimber
Canik
Taurus
Caracal
The only one missing I can think of is Colt. What's odd and rather humorous is that both Beretta and S&W have a long record of making pistols with mechanical safeties and metal frames. Now both of them have moved away from both of those attributes completely. Beretta is especially entertaining as they attempted to fix the Beretta 92/M9 problems by offering the M9A3 as a replacement for the MHS trials. Beretta was politely told to go pound sand. Immediately after that they dropped their new wonder pistol of manual safety/decocker and alloy frame design for a completely polymer framed striker fired gun... I'm sure some will say that's Beretta innovation; When it's really just a pathetic attempt to jump on the polymer striker fired pistol band wagon and try and pick up the scraps of MIL/LE contracts that might get left behind by others, namely GLOCK.
You asked about reliability. Have a google look around and read the many torture tests done to Glock pistols. Notice that the vast majority of LE and elite LE units(counter terror/swat etc) and SF MIL units use Glock pistols. Here's a quick grab from the interwebs about high round count Glock pistols.
http://www.glockforum.com/How-Long-Will-Your-Glock-Last.html
https://www.calguns.net/calgunforum/showthread.php?t=360611
And another with some details.
http://www.tactical-life.com/combat-handguns/glock-17-9mm-torture-test/
I'm sure that's your M.O but I already know I have the best make/design of pistol around and have had for years. I surely wouldn't seek validation on this forum if I ever was in the market for it.
Good choice but if you can't shoot any pistol well then it's you that needs work not the gun.
