Have just been taking this beauty for a few laps of the Nurburgring. I play with a racing seat and G25, 50" plasma and a good surround sound system. Of late I've been mostly playing the Nurburgring, with 'Old' track conditions and temp around 16*, so naturally a lively surface. I drove the car initially on Semi slicks, but when I realised there were other options, I went over to the 90s street tyre.
I'll try and group my thoughts together into sections
I've always loved the Diablo, and the Jota is the best example, I was really excited to try it out when I saw this mod.
Graphics / Model:
It's a fantastic model, looks brilliant, headlights pop up and down smoothly, interior looks great, nice selection of colours and love the couple of colours with different interior options.
I found that the cockpit steering wheel rotated further than my actual wheel. I've never noticed this on any other cars in AC, it threw me off a bit so I just disabled the virtual wheel. I don't know if this can be related to the mod or not, I'm fairly new to the mod side of things. Also, the interior dial illumination, whilst fantastically italian, does render the dials fairly impossible to actually read. A minor issue, frankly it's cool enough that the pop up headlights work!
Sound:
It sounds fantastic, both in car and in replays. Engine has a nice range of sounds that blend well, the pops /gargles on the overrun sound natural and happen at appropriate times. Is it possibly unrealistically loud? Hard to say as I've not had the pleasure of experiencing a Jota in person, and my only ride in a Diablo was as a young teenager in a VT, so who am I to judge!
When changing gear really quickly (admittedly unrealistically so given the fairly agricultural shift in the real car) the revs in the next gear do sound a little flat after the crescendo of the higher rev range. It's hard to describe, but it can sound a little synthetic. This is easily avoided by changing gear more 'appropriately' though, so a very minor thing. The sound made me laugh out loud multiple times as it's ultimately just a really enjoyable noise.
Physics / Handling / FFB:
Obviously I haven't driven a Diablo, so really I'm just commenting on things that seemed a bit unnatural. I know the car is a beast in real life that demands respect and smooth inputs, one that will bite you if you so much as breathe funny, which is exactly the kind of car I love to drive in sims!
As others have mentioned, the brakes are a little keen. Even braking progressively at over 100mph, full pedal travel will lock the wheels up (brake power reduced to 80%). Now as I said in the first paragraph, I'm not exactly in prime grip conditions, but for a 90s supercar, this just seems a little bit too powerful. I could understand at low speeds being able to lock them up or when stamping on the brakes, but they do seem a little too good for the tyres.
The steering feels very keen, to the best of my knowledge the Diablo doesn't have a reputation as a darty / pointy car, so this seemed perhaps a little unrealistic. It is also very keen to step the back end out under almost all conditions. Don't get me wrong, this makes it more fun to drive, but it does seem a little unrealistic that cornering over 120mph the back would so easily start to swing around.
I found that setting the rear anti roll bar from 1 to 0 made the car more of a 'pig', which is how I've always interpreted that the car handles. As in, a bit more reluctant to turn in, more snatchy when it does let go etc. It by no means made it handle BETTER, but the extra understeer and slightly calmer rear seemed a bit more like the big bad Diablo I've read about (obviously with the caveat that it'll bite your head off at a moment's notice under power or excessive weight shift)
This may be related to my G25 to be fair, but there also seems to be a bit of a limp area around centre and about 45* either side. The steering still responds, but the FFB is appreciably lighter and there just isn't a lot of 'feel'. This could equally be representative of slightly vague 90s Italian steering though!
I think that about covers my thoughts on it. Either way, it's fantastic fun, and for the price I really couldn't ask for much more