I haven't used those particular products, but the fruit bases are probably comparable to the Vintner's Harvest fruit bases and the concentrates similar to the Alexanders brand. Just like there are various wine kit manufacturers...
I haven't use the fruit bases, though I know folks who do -- but I've used some of the Alexanders' wine juice canned concentrates along with my own fruit (steam extracted juice) and been pleased with the outcome.
On other forums I've seen both positive comments about the canned concentrates, for what they are, and also scathing comments about how the red concentrates are just *&@^#*&^. It all depends on what you are trying to craft.... high end, premium wine from canned concentrate? I think not; good enough everyday table wine with a bit of "I made it myself" pride and crafting your own - definitely something there.
I made a Blackberry-Barbera, and a Pinot Noir based all grape with indeterminate variety of table grapes. Not high end stuff to be sure, but neither was the blackberry juice (it was at least 10 years old) and the grapes were from the neighbor's before they ripped out their food garden to put in all ornamentals. Both were 3 gallon batches and cost me all of the cost of 1 can of concentrate, the sugar, and a packet of yeast (each).
Very Low Cost + Serendipity of Found Materials balances out Not Premium but OK to equal Pretty Darn Good! in my book, other folks may have a different mix of criteria.
I also make fruit wines using the welches concentrates as a base, and there is a step up in the vinifera concentrates over frozen breakfast juice -- it's all a matter of what you expect and what brings you satisfaction. There's definitely a place for these concentrates in the spectrum of wine making choices.
