Unlike you, I've actually been there. You seem to have to use internet stock of armchair Larry.
Come on now. I'm just having a little fun.
I said DP not approach into KTEX BTW.
Jet engines would probably help the most, so where do you draw the line?
Reality is you have to do the best you can with what you've got and spend your money where you think it will benefit your operations the most. If I lived in IL I wouldn't own an aircraft that wasn't FIKI for example. However, in the mountains SVT increases safety IMO, just like I've said a 100 times.
Since I fly the Rockies year round in most weather, I will suggest to you (humbly of course) that ANY piston would be ill advised to attempt to fly traditional IFR operations on some days. Even turbocharged twins will encounter conditions beyond their capability up here, it happens every year, year after year. Often we are forced to use combinations of operations in pistons. For example: depart VFR, climb up through a hole picking up a clearance on the way up (as we pass through the MEA's), maybe topping in the high teens or twenties. Same thing coming down. Sometimes its better to cancel and circle down VFR through a hole, because flying an approach in the heavy icing in any piston would be suicide. Other times we fly low down a valley (not scud low), but VFR under the cloud layer, until we can find a way on top without turning into a popsicle.
We have a tongue and cheek saying up here, "When the weather's to bad for IFR go VFR". Funny, but there is a lot of truth to it.
I'll even invite you to come up in winter and you can see for yourself, why pistons need VFR, and therefore why SVT has value in our operations. There have been many, many, days I have used the above to come and go, when the only other traffic was well equipped turbines.
BTW- I live just south of KTEX and fly all around this area, but you haven't guessed anything right about me yet, so no surprise.