What I like about iRacing driving experience is a sum of many things, it's not really possible to point out just one thing and say "that's why it's worth the money".
-Much more limited setup options, you can't tune brake pressure and gearing to exactly match every track. Another LFS setup issue I have is that most WR sets are designed for weird driving style such as curb-jumping, dipping into grass for quicker turn-in or just shortcutting much as possible. I'm doing ok and I'm only few tenths slower than fastest guys while using very stable setup that I've adjusted to my own driving style.
-Track surface detail adds more challenge in finding the optimal line, Lime Rock Park is prime example with it's bumps, camber changes and concrete patches. It's much more difficult to run consistent laptimes and pushing over the limit tends to have bigger concequences, cars are not that easy to drift around the corners if you enter too fast.
-Fuel and tires, you can't see tirewear and temperatures while driving and even fuel estimate is just an estimate. In LFS I always drove with tire info visible to adjust my pace so temperatures stay within optimal range, but in iRacing I have to pit in to update the readings on temperature and tirewear. On ovals it has major effect when you're wondering if you should go in under next caution or not while you still have plenty of fuel on board and so on...
Then there's the whole system how race seasons are set up and so on, but it's not directly related to driving feel although I like it very much, much more so than closed leagues.
-Much more limited setup options, you can't tune brake pressure and gearing to exactly match every track. Another LFS setup issue I have is that most WR sets are designed for weird driving style such as curb-jumping, dipping into grass for quicker turn-in or just shortcutting much as possible. I'm doing ok and I'm only few tenths slower than fastest guys while using very stable setup that I've adjusted to my own driving style.
-Track surface detail adds more challenge in finding the optimal line, Lime Rock Park is prime example with it's bumps, camber changes and concrete patches. It's much more difficult to run consistent laptimes and pushing over the limit tends to have bigger concequences, cars are not that easy to drift around the corners if you enter too fast.
-Fuel and tires, you can't see tirewear and temperatures while driving and even fuel estimate is just an estimate. In LFS I always drove with tire info visible to adjust my pace so temperatures stay within optimal range, but in iRacing I have to pit in to update the readings on temperature and tirewear. On ovals it has major effect when you're wondering if you should go in under next caution or not while you still have plenty of fuel on board and so on...
Then there's the whole system how race seasons are set up and so on, but it's not directly related to driving feel although I like it very much, much more so than closed leagues.
There is a LOT of information of the kind you're asking for in the other threads.