I have seen the swan necks, and never used them.
There has been a couple times when I have thought about it, but all in all, I think I would just stick with a "standard"
I run a 250 and a 130. It all comes down to money I guess. You can crank the big machine down, and run smaller wire, but I tend not too.
Here lately, I have been runnining .030 in the big machine, but usually I was running .023 in the small and .035 in the big, then I run .045 in the suitcase with the mobile unit.
My 2cents is to run I quality wire and consumables. I can tell the difference.
To acknowledge MadRef though (who built a ton of stuff and I respect greatly) he would reccomend HF wire.
Kind of comes down to try a roll of each and see if you can tell the difference.
As to the HTP guy, yes, he is pretty much correct, but what is left out is that you will need to change wire. While this is not a big deal, I always kind of equate that to watching the shopsmith guy in the mall work with the shopsmith. He is flipping this thing this way and that and it all seems to go so smoothly.....
Then when you get home..
As to the Stitch and Spot weld functions (and this will be mighty obscure if you do not follow this type thing) In the movie Blackhawk Down The Ranger company commander looks at the D boy in the chow line and starts in about his weapon is not on Safe...................
D boy looks at him and holds up his finger and say's "this is my safety"
As a side note maybe you have to be in the environment to understand.
Anyway, I would certainly not pay extra for spot or stitch functions.
You will naturally do it with your trigger finger and have better results for repair welding.
I am making an assumption that you are not doing any robotic or production welding.
I see by your tag line that you may appreciate the Blackhawk down reference.