I have a 2008 D-VI. Any issues I have had with were fixed by Koaloha for me under warranty. Even though its a 22,000km return trip to the factory, with a 6 week wait.
Assuming that it was bought as the premium for full price and not as a second, and the owner is the first owner, the only reason it should have an issue is if the owner did not get it fixed by Koaloha. It would have to be something bad to not be eligible for the Koaloha warranty, so that is unlikely to be easy to hide.
I do not know what happens to the warranty if you are the second owner.
The biggest issue I have noticed with the DV-I is that if someone picks it up for the first time, they will fumble and it wont feel like their guitar or sound like their guitar if they have been a guitar player. Same applies for a uke player. They need to get used to the different voice and feel, which might take 10 focussed minutes. One or two very good guitarists have not been able to cope with the difference and they have given it back to me without trying it for very long because they could not get the difference, it was like it hurt their ears.
The other issue is musical. If you understand that middle C is a popular reference point in music. Its the middle-C key on a piano is at C4, and the middle-C note on a guitar is at C3 (fret 3 of A string), there is an octave difference. On a ukulele middle-C is at C4, like a piano, on the open C string.
On the D-VI, because of its note range when tuned A2 (110Hz) to A5 (880Hz), you can arrange your music using C3 (A string fret 3) as middle C, like a guitar, or C4 (open C string) as middle C like a ukulele and piano. The lowest note is A2, which is in the grey area between bass and treble clefs. In other words it has a higher voice which can be in the treble part of the music on all strings, you do not have only use the low string for the bass par
So you can transpose and play it exactly like a guitar. You can leave out the two low strings and play it like a low G tenor uke. Or you can take advantage of A to A and have a new arrangement which is sort of half way between guitar and tenor uke. At least three musical choices.
