I have owned 4 of them. 2 fivers, and 2 fourers. Combustions and NG3s. While some negatives has been aired here, it's mostly in the taste kind of thing. Personal. Me as a not special tall person or with big hands, finds all of them a little too clunky and cumbersome to me, even if they do not neck dive. While not "negatives" as such I've found some, more likely, caveat emptors, as most of them has dawned on me slowly and not immediately detected. I list them in no particular order:
1. Price, which are debatable, since now the lower priced ones comes from Asia/China.
2. The strings. It's still VERY few manufacturers who produces extra long string sets, while it seems to be ONLY the low B that's needed extra long, not the rest. Maybe hence they release the new SP1 series from China with just a 35" inch on the lowest string. Perhaps.
3. What I find difficult to master, is the very thin mandolin like frets (they actually use one size above actual mandolin frets). Especially when RELEASING a note from any fret, and that's even on the high G-string which has regular scale at 34". No matter the action, there's always a slight fret buzz heard when releasing the note. Lifting the finger from a fret. I've even seen a YT video by someone who made a review of one NG bass that addressed this, and it's like this: I don't experience the same buzz on other basses which are pararell frets and thicker, taller frets. As it is, I have yet to find that YT video again, as I can't remember who it was that recorded it. But I was not alone on this one, for sure.
4. Output jack can't take angled plugs. To me angled plugs are a safety thing, they don't risk of "un-jacking" accidentally as much. And the thing is with angled plugs is that you can let the bass reside on whatever, the plug resides on it's shell, and not the cable which bends it too much so it can cause havoc inside.
5. My use of the 4 strings, that it was tuned to BEAD and I used a capo on 5th fret to get it in tune to regular EADG tuning. And it sounded good up there on the low B string. The thick low B still sounds great at 36" scale length, above 12th fret as well as open string. So if I had to play in Eb just drop the capo one notch and one's good to go. Not a negative though, but I found the use of a 5 string quite superfluous then.
6. The active thing with 2 batteries rubs me the wrong way. And subsequent EQ possibilites on the bass. Since Sheldon himself flaunts that fanned frets thing, evens out tension and you don't have to turn to outboard effects such as compressors and eq's to tame the sound, timbre, it seems to be counterproductive. I didn't use the EQ onboard at all because it wasn't needed. Kind of superfluous too. Which is like someone already told us in earlier posts, that it is all kind of sterile, neutral, and not characteristic enough. Which meant that I tried to remove the batteries and just use the switch in passive mode, which isn't possible, it needs to have batteries. On other basses with this system (switchable passive/active) this is possible. So one can't turn the switch to passive when playing live if the batteries starts to go south. What's the point of having that switch then? But on the other hand Dingwall does the all passive thing too. But not on all models.
7. The need for 3 pickups stacked close together in line with each other beats me. I liked those 2 pickuped ones with more space between them, i e the middle pickup removed. There's very little difference between them. It seems like Sheldon used them as an excuse or substitute for a "ramp" instead, to rest your fingers on while shredding. There's simply not enough space to thumb, slap in the position where one slaps the most. I screwed down my middle pickup as far as it went into the body. Bored me silly. Beats me.
But points 3 and 6 bothered me the most. Of course, someone else couldn't care less about this, but so it was with this thread. Negatives. Not negatives as such but more marginal notes of idiosyncrasies. Mind you that ALL of the basses I own, and owned, has(have) had their idiosyncrasies and caveats too. No matter how posh high end, or cheap builds or anything in between. The trick is to learn, and play, and master all these kinds of idiosyncrasies with any instrument and learn to buck them while playing, say dead spots on another instrument. And "camouflage" the errors. Like angling the fingering according to the bridge and so on. That's part of the playing actually.
But other than that Dingwall's good. Methinks. ;-) I spent money on 4 of them. 2 of them brand new. 2 of them second hand. Don't regret it at all.
), the hardest part begins now: wait for Sheldon team to build it, it's going to be a hard period of time for me thinking of the moment in which I'm going to have it in my hands, can't wait 
