Have an SA35 and the L9A1.  Happy with both.  Honestly the SA35 was nicer than my Browning, which I sold.

What is the finish on each?  Presume the Girsan is Cerakoted?

Finish, trigger, etc is excellent.  Haven't got the range yet but I'm confident it will meet my expectations.  I'm into it for right at $500 and I think it's a great value at that price point.

SA35 is blued, and nicely at that.  The L9A1 is a matte blue, black chromate (whatever that is).  Very much keeping in it's character.

Sa35 is not blued. I believe its parkerized. Its just not a rough parkerizing.

Sa-35 direct link.

Damn! I always thought it was parkerized. I’ve been wrong all this time.

I recently got a Girsan and it appears that the parts are not interchangeable with my FN.

Trigger was very heavy.  Take-up was gritty and inconsistent but the break was crisp.  I removed the magazine disconnect and the trigger lightened significantly.  The grittiness and most of the inconsistency disappeared from the take-up.  Trigger remains crisp.  It is still a couple of pounds or so heavier on the break than my FN.  Slide fits to the frame very well and is nice and slick.  I hope to shoot it this weekend.  Surprisingly, the CA version came with an optic cut, so I am going to try the Holosun EPS Carry on it.

I think you would of been happy with the springfield. I bought a couple of c&s trigger kits to use on my springfield. Its not needed.

Are the Turk/Springfield guns not part compatible w/ original FN HPs?

I think it depends. I tried to swap the extractor on a Girsan with a NOS Browning one and it did not fit. The rear of the channel extractor on the Girsan slide is too short. It might have worked if I filed off a bit of material.

"Some fitting may be required"

It wasn't an option as it is not on the roster.  The Girsan CA model is the only Hi Power on the roster.  Local store had it for $599, which is a little high, but after transfer fees and shipping it would have been about the same at best from the dealer with the lowest price I could find online ($509).  I wanted a Hi Power that was registered and I could actually put on a CCW permit, as I intend to apply for one in the near future, and did not want to spend too much money, and while I had a contact at Arms Unlimited who could have hand picked a C&R eligible alloy-framed FN Hi Power, they sold out by the time I would have been able to get around to trying to get one (while more expensive, it would have saved me the new firearm excise tax if AU had charged CA sales tax); I would have needed to wait until January to get a 1975 alloy framed FN.  Used market intrastate or for C&R eligible stuff is a bit high right now (same shop I got this one at wanted the better part of $3k for a fairly basic Classic FN Hi Power).  I have an FN already, but it is not appear to be in the registry and I do not intend to do anything to fix that.

I did take it shooting the other day.  I'm not a great pistol shot, so it is hard to gauge accuracy, but the groups did not seem all that different from the FN; a little wider, if anything.  It was shooting 6" low and 4" left at 10 yards.  It was better for elevation but not much better for windage at 15 yards.  With the Mec-Gar 15-rounders I would get a weird stoppage about half of the time.  The slide would lock back after the second to last round was fired.  I also had a couple of stoppages, including when initially chambering, using the Mec-Gar 20s and a stoppage mid-magazine on a Mec-Gar 13.  No hiccups using a KRD 17-rounder.  I would say I probably got 7-8 stoppages out of 200 fired.  I may have only gotten one with Blazer Brass.  The others were with S&B or remanufactured ammo.  All ammo was 124 grain standard pressure.  I did not test with HSTs but I will in the future.

The FN parts don't seem to be fully compatible.  The slide stops will not interchange at all.  The FN slide will slide onto the Girsan but the Girsan will not slide onto the FN with a barrel installed.  It reaches a hard stopping point early on.  Without the barrel the slide still does not fit right and it is prevented from traveling by the hammer, which seems to sit too high for the Girsan slide.  The barrel lugs will not lock into place on the slide from the other manufacturer.  Hard to say about barrel compatibility otherwise, as the alloy frame I have has the round cam and the barrel is different accordingly as well, although supposedly there is some cross compatibility with the more traditional cam.  The recoil springs and guides also did not interchange.  I'll look again, but I think the Girsan is noticeably longer.  The bigger issue is with the guides, though.  Grips interchange, but I forgot to check the checkered plastic stocks I ordered for the relief on the right side for the ambi safety and so I can't use them, as they do not have it.  They fit otherwise, though.  I am not a fan of the palm swell type stocks that were made for many of the MkII and MkIII Hi Powers, which is the style the Girsans have.

I wonder if replacement mainsprings will work with it.  I had thought of moving to the 26 lbs type, or something in-between, as a way to lighten the trigger without too much work.

Euro Optic made me use my old address down in SoCal for delivery since it is still my billing address, so I have not had a chance to see how the Holosun EPS carry fits or try shooting it with the optic mounted.  I should be able to pick it up this weekend.

I've had my L9A1 out to the range three times now and it's still 100% reliable.

Only issue I have is when I grip it too high (like I shoot the Glock) and ride the slide stop accidently.
When I remember to adjust my grip then it's back to 100%.
Also I have to remember to let my finger out just a little farther to get to the re-set.
I'm used to a short reset from shooting 1911s and Glocks.
Both are common problems for me with all HPs and is a shooter issue and not the guns fault.

Over all though it's a great little pistol and I love the way it shoots.
I ran a mag full of mixed JHPs through it on the first range session and it fed all of them including the Winchester 147s.

Where can I get a brass bead front sight for this thing?