I have to dissagree David with you here.
My best lap time on Mid Ohio during a test session with full fuel and fresh tires is 1.17.6xx without hunting best times. If you are able to keep this over 46 laps, which is about a ful fuel tank, than you are right. If not, than not. Hell, it isn't even possible to keep it in the 18's.
Doing 20 laps few setups adjustments between is not a propper test for these cars. It is basically the same as you see often people saying who tried the ISI corvette "oh dear the car is sliding all over the place, no grip at all, crap car" The thing is those tires punish you at the end of the stint if you overdrive them at the beginning. The last 15 laps or 20 in Mid Ohios case for example.
The tires punish you very well if you don't take care about them. At a certain point they just don't come back anymore. If they overheat to often you are more or less done. They just don't come back and you loose on tracks like Mid Ohio about 2 secs a lap or even more. And that is without flatspoting or extreme sliding all over the place, just pushing. Of course on tracks like Sebring it a lot easier to manage them.
But to say there is no strategy possible is way over the top or that driving has no influence. You are as well free to double stint the endurance tires if you can keep up the pace.
But honestly, expecting those cars to behave like the ISI 2009 Vette is just not right.
The bodywork is wider, the wheel base is wider, the tires are wider, the aero is better.
All those things lead to a more stable car generally. It definitly is not possible to go a full stint flat out in my case, no chance. There is a lot of setup work to do for every track to manage the tires properly. At Bahrain for example you have those last two uphill turns.
If you don't setup the car accordingly you will loose there time after ten laps bigtimes if you go flat out and then you have the next right hander which gives your left front the last thrill. This will keep on going in the slow chicane where you can lock up and so on and so on.
That said there are of course things with this mod which are no perfect. The URD mod would benefit of chasis flex big times as it is not implemented yet. That is probably one of the reasons why the cars are that stiff and of course the suspension base setups.
The cars tend to bounce of in a weird way, just like the AC cars, as it is something wrong with the suspension base setup. To a certain degree you can dial it out with setup work but it is still noticable on some corners here an there.
The last thing, they need more drag added to get about a 1 slower over a lap which also has an impact on the driving.
Seriously now one should take those cars for what they are and not what ones wish them to be. They are not GT2 cars from 2009, They are GTE cars form 2013 and they seem to replicate those cars fairly well if you ask me. Go ahead and compare an F! car from 2009 and 2013, I guess you wouldn't expect them to perform the same way.
As for the rain aspect, there is no possible rain driving for now on a noraml RR rate.
As soon your tires get to running temps you are aquaplaning all over the place.
So rain racing currently not possible at all.
EDIT: Having wider tires also means you have your peak performance longer but you need a bit longer to get there BUT in our case the tires are already preheated so this is obsolete.
example by this nice lady here