Wayne,
The winepress.us site you posted is actually based only about an hour and a half away from my home. I'm also a member there and have been threatening to pay them a visit for the past several years.
As for using either fresh grapes or a kit, I will say that a nice wine can be made from even an inexpensive kit.
In the past I've used both the Wine Expert Vinter's Reserve kits (which are in the $70.00 range), as well as California Connisseur kits that are only marginally more expensive.
I've also used some of the canned juice concentrates like Alexanders which are about $20.00 per can.
In each case I turned out a nice daily drinking wine but for some reason only after a LONG aging period. Most others find their kit wines to be good at 6 months to a year but I felt they were undrinkable until at least two years had passed and in one case, three.
Now concerning juice wines and kits, as Wayne said, they will only have the potential to be so good.....
The reason for that, (in my opinion) is because you are re-hydrating the juice with water. Most kits have around 2 - 3 gallons of juice and they are made to a 6 gallon batch. Considering that this is the case it's even more impressive that you can turn out a pretty nice end product.
Another option that is available, (although MUCH more expensive), is pure juice kits.
These contain 6 gallons of pure juice and range in price from $150.00 - $250.00, depending upon the quality of the grapes the juice was made from.
This would, by far, be the best way to go but again the quality comes at a higher initial cost. If I'm thinking correctly, this type of kit should produce something very close to a wine that was made from fresh grapes.
Even though the pure juice kits are high, relatively speaking they really aren't that bad.
Considering that you will get about 30 - 750 ml bottles from one of these kits, the price per bottle, (even on the most expensive), comes in at around $8.00 per bottle.
A few weeks ago my cousin and I drank a Pinot Noir that he had purchased. It was a $75.00 bottle of wine that should have been wonderful. Unfortunately neither of us were that fond of the wine, even after letting it breathe for over 2 hours.
I would much rather spend $250.00 on a good kit and end up with 30 bottles of a wine that is sure to be very drinkable than spend even $75.00 on a bottle that I did not like at all.
I've just gotten back into wine making in the past few weeks and have been doing a lot of reading. I don't really see myself ever going the fresh grape route, simply because I don't have the room for the required equipment, or the funds with which to purchase the equipment or grapes.
I do, however, see myself moving up to the all juice kits after I get a few less expensive kits under my belt.
Right now I'm just sort of brushing up on the things I learned a few years back and trying a few tweaks to the kits, to make them more to my liking (acid/tannin additions and adding chopped raisins for extra body).
All in all I'm having a blast with it, but before I begin an all juice kit I have a standing date to call Wayne and pick his brain.
What's amazing to me, is that making certain varietals of wine, is even possible in the home setting.
I mean here in Illinois, (say 20 years ago), you basically had one choice when it came to a grape wine.....Concord.
Now, thanks to the internet, I can make an authentic Burgundy region Pinot Noir or one from the Sonoma valley if that is more to my liking.
Honestly, that just blows me away.
Dave