The Masters and GM shooters I shoot with all shoot this standing. Call me lazy, but it seems they already figured out what is fastest so I just follow suit. It seems that the table would get in the way of the draw if you were sitting. I don't necessarily follow suit with the M and GM's on long courses because my skill sets are different than theirs.
There are volumes of data on this in the reloading portion of this site, but my 38 SC load is 10.1g 3N38 with WSR primers and Montana Gold 121 IFP out to 1.240 OAL.
The effectiveness of the practice, be it live or not is even more important than rounds down range.
Too much self esteem is not a good thing just prove yourself, don't rant that "what if" ... I would be the best there ever was. I call that an excuse!
I use the flat inserts in my SV Limited and Open guns and one of my 1911's because I like the feel. I'm sure it's just my perception, but my trigger finger senses the reset of the trigger better on the flat then the curved inserts.
I have 3 SVI's and can tell you the salesmen you are dealing with are just trying to shake you up. The SVI's do take some time to get built mine have all been <1 year (in the U.S. which shouldn't matter). Everything else they listed is rubbish and not true.
I also own and STI and the comparison I will make for you is a Ford Mondeo (STI) to a BMW (SV) as far as build quality.
Good luck!
Since you can't shoot Production, L10 is a good division for you. You would have several things going against you in Limited; mag capacity, minor vs. major etc.
Just go out and have fun, the rest will come with time!
I use a 4" BWC Wilson (steel frame) in a Bullard leather holster which holds it tight to my body. I sold a 3" Kimber Ultra CDP because every time I shot it my teeth hurt. Both guns are/were practiced with often and have been 100% reliable.