There are some things to point out about the 45 Super as I've played with it somewhat extensively.  First is that using Starline 45 Super brass it can be loaded to duplicate 460 Rowland, the one drawback to that, if you want to call it that, is that the gun will require using a compensated barrel.   

But also what I did was to lengthen the throat in the barrel in order to allow heavier (and sturdier) .452" revolver profile bullets in the .45 Super.  Might not seem like much but it opens up the operating range of bullets which can exceed 300grs.  There is truth that just running .45 ACP bullets fast doesn't really prove much as most of those aren't capable of handling the velocity real well, a 230gr might be okay at 1000 fps but act differently at 1350 fps, or a 185gr @ 1600 fps, which is doable from a 5" .45 Super with a comp.  But run say a 250gr XTP, a revolver style bullet, to over 1300 fps and you've got a pretty big hammer.  Similar things though could be said of 10mm, not all .400" JHP's fair well at higher speeds, many in fact do not.

SOLD

I love the 10mm, I have a number of them but that being said, for dedicated hunting, one would be better served by something like a .44 Magnum.   I do get that the G20 and even G40 are smaller than most .44's and hold more ammo, and especially for a dedicated hunting handgun against potentially dangerous game, a 44 will serve anyone better.   Around here the biggest game I'd hunt would be whitetail deer, so the 10mm is fine, but it wouldn't be my main gun against something nasty, maybe backup at best.

I don't see a downside, frankly I think the 10mm should be SP anyways.   For reloaders I guess the one negative would be having to sort brass.

Wish I had a neighbor like you!

For what it's worth I bought a box of 155gr Hornady XTP 10mm and they're SP as well.

The G20 is a fine gun, especially Gen4.  I will say though, you don't need an aftermarket RSA with the Gen4, Gen3 yeah but Gen4 is good to go for all loads.

Concerning the idea of using a FMJ loaded hot, I don't really see a lot of point to that but that isn't to say there is zero point, maybe somebody would use that for a load focused solely on penetration.  The only point where I do think it's useful would be for practicing but only if what you're going to be carrying is the JHP equivalent. 

Now in general, I think the sweet spot for most handguns rounds is less than absolute maximum potential but still more than what would be considered typical factory velocities.  This holds true with nearly any of them, be it .40 or 10mm or .45.  It's fun to see what a cartridge will do and I've pretty much pushed .40, 10mm and 45 Super about as far as they will go, but I don't really see an absolute need for utilizing such loads with the possible exception of using them for hunting, but really never for social work.   I think it's about the blend of having more power than "normal" but with enough margin of safety as to be utterly reliable.

I have used their bullets in the past, nothing wrong with them.  That said, it's cheaper to shoot coated cast bullets.

I've got some coming, I ordered mine through targetsportsusa.com

Once upon a time Speer had a run of 200gr Gold Dots in .40 S&W and moreover, some ended up being available through a third party to reload.  I had some of the recent 200gr Gold Dots for 10mm Auto and to me they looked just like the 180gr Gold Dot, at least the hollow cavity did.  I'm not saying Speer didn't design the bullet for 10mm, but it wouldn't surprise me that they just made the 180gr variant longer rather than actually designing it new from the ground up.

Seems like the V-Crown did a fine job.  Saw very similar results when someone shot a deer with a G35 using factory Winchester JHP, deer dropped immediately and bullet stopped just shy of exiting on the other side.   I wouldn't worry about wanting a lot more penetration unless you're after larger animals, whitetails aren't tanks.

I'm utterly bored to death with the 9mm craze.  Oddly I did buy a G45 but I just can't warm up to the 9mm, I do see it as a sufficient cartridge for self defense, but in a minimalistic kind of way.  I'm an oddball I guess in that I really like the .40 S&W but everyone loves to hate it for some reason.  Everywhere you turn it seems like you see these hipster millennials with beards wearing shades, dressed like they're all hardcore operators, carrying these tricked out 9mm's with grip jobs and red dot sights...ughh.

I think it's easy for people to defend what they're invested in, so if they really believe that the 9mm is as good as anything else I think the root cause of that is them defending they're choice more than it being based in reality.

I don't really understand why Glock thought the features of the G45 were really worthy a new model designation, it's basically a black 19x with a few minor differences.  Now that said, I do like the Gen5 Glocks for the most part.  At first I had zero interest in them (mainly due to them being 9mm only for now) but I bought a G26 Gen5 and then a G45 (both gone now)  and the finish is better and so is the trigger, it's pretty darn good.  I've had the G43 in the past too and the new Gen5 Glocks basically have the same trigger setup, it's got an even shorter reset than you see in the earlier generation Glocks. 

That said, I'd jump on a few Gen5 .40's if Glock ever decides to release them.

Good shooting!

I initially thought the SRH platform was a bit much for 10mm and had thought a GP100 would be better, but I'm now leaning towards getting a SRH 10mm and getting it reamed to 10mm Mag.   The SRH is very strong and with some resized .41 Mag bullets, the 10mm Mag could prove to be quite an interesting project.

Interesting to see that because I've recently been thinking about getting the 6.5" SRH 10mm (although Lipseys is offering a 7.5" version) and getting it reamed out to 10mm Mag.