although SA has good customer service, where the sight alignment and installation comes in, they may have some quality control issues.
Muffled cough sounding vaguely like "Bull(droppings)"
I'd ask you to prove this and no doubt you could go into some discourse that would seem to do so and the war would be on. Instead let's look at the mathematics (and practicalities) of sight alignment. By doing that we will have some reasonable standard upon which to base a discussion instead of a flame war.
There are two distinct elements to proper sight alignment:
1) Pattern, also called group, which can be thought of as tightness, i.e. three or more shots, made under identical conditions where the bullet strikes are in obvious close proximity to one another. Typically a circle of 2 inch diameter or less will completely encompass all hits/holes.
and
2) Placement which is where the center of the cirlce containing the hits falls in relation to the actual point of aim-a dot or pair of crossed lines typically, but a bull (inverted U) is sometimes employed. Placement of the pattern should be within a circle originating from the point of aim with radius of 5 inches (for a defensive/combat pistol).
Let's pause to recap: For a target 25 yard from the muzzle of a combat pistol, a two inch diameter group of 3 or more shots within 5 inches of the point of aim is indication of both sufficient pistol accuracy and adequate sight alignment (zero).
Why not align the point of aim (POA) EXACTLY to the point of impact (POI)? Simple and statistical! Unless you have means ($'s) and opportunity (availability) to acquire a very large quantity of ammunition (say 10,000 or more rounds), there is a measurable probability that the next box you do acquire will print a pattern at some other radial of the 5 inch circle--in fact, there is finite probability that that next box will print diagrammatically opposite the current box of ammo--along a radius directly opposite the first and equally far from the POA.
Chasing the elusive point of impact would involve an endless series of sight adjustments; a process that weakens and possibly damages either or both sight and gun. If you need such capability,an adjustable target sight is preferable.
Are these 2 inch and 5 inch numbers magical? No. The 2 inch group size is another statistical average. Most feel that a stock combat pistol barrel is of sufficient quality at this level or repeatability. A custom or match barrel is typically 1 inch groupings; some are even less. Occasionally a custom maker will claim a 1-1/2 inch accuracy for groups from their products.
The 5 inch number is derived mathematically from the sight adjustment formula (See the appendix of the Lyman 49th edition). Basically it's a problem of trigonometry called similar triangles. To move the point of impact 5 inches at 25 yards, a sight with 5 inches of space from post to notch must be adjusted by 1/64 of an inch. 1/64 of an inch is the smallest gradation on the standard machinists pocket ruler; i.e. the smallest movement a gunsmith can make easily with visual confirmation. One sixty-fourth of an inch is approximately 0.0156 inches, "15 thousandths".
Interestingly, the math is nicely complimented by fact on the ground. Using the same similar triangles calculation our placement circle shrinks to 2-1/2 inch radius (5 inch diameter) at 12.5 yards. It's 1-1/4 inch radius (2-1/2 inch diameter) ar 6.25 yards muzzle to target. At typical self-defense distances (arms length to 7 yards) it's almost impossible to statistically differentiate two different points of impact from combat handguns--you cannot tell which of those two boxes the round originated from.
So, for a combat gun with fixed sights, get yourself a stack of 9 or 10 inch diameter round paper plates, some colored adhesive dots 1/2 to 1 inch in diameter and a can of Coke (or other preferred soft-soda). Stick the dots on the center of a plate and attach it to a target stand 25 yards from a steady and stable shooting bench.
Carefully fire three shots at the plate from a firm rest (sandbags) on the bench using the dot as your point of aim.
Drink the soda.
If all three shots hit the plate and are grouped so the top of the soda can completely covers the holes, your gun is sufficiently accurate and the sights properly aligned for defensive purposes.