For 6-7 years I'm driving only LFS. Becouse of:
- Physics model
- FFB model - with G25 superb feeling
- Really good and smooth (100FPS constantly on an pretty average computer) online racing (community)
- Totaly adjustable per-car-setups
- Realtime -> on-line statistics
- New car - VW Scirocco comming !
- New Rockingham track comming !
- From scratch re-programmed tyre-physics comming (together with ABS, traction control, etc. modelling)
- (maybe) car-body-parts falling apart when colliding with others/barriers
- etc.
Cheers racers! 
All good
I think I will try LFS if iracing doesn't work out.
Where are you from, mate?
If you are Aussie then you may find getting an official race (races must have a certain number of people in them to be classed as "official" and score points and full safety rating) to be a bit difficult - particularly in the higher series. It isn't too much of an issue when you're starting out - there should always be a Legend race (rookie oval car) and a Solstice race (rookie road car) should come along often enough. Above that you need to pick your times.
If you are in America then there isn't really a problem and if you are in Europe then it's somewhere in between.
Personally I love the game. I'm only running the one series this season - Lotus 79 - but am having heaps of fun (when I can find an official race!). I'm a Pro licensed driver but am not bothering to run in that series, mainly because it doesn't use the Lotus and I only have time for the one car.
If you're thinking of joining then do so ASAP as we are nearing the end of a season. If you join now, you can run the races you need to to go from a rookie license to a D license for a full season in that class (and the D license car, the Skippy is probably the most fun car in the game).
Thanks for the heads up.

Which series should I be aiming at joining for next season? Skip Barber?
Yeah I'm from Aus. It hasn't ever been a problem before though, in GTR I had 30+ car races okay with a 300 ping and close racing wasn't impeded. In rfactor with 30+ cars it's even better. The time zones are annoying but I've been known to race at some odd times in the name of sim racing. FSR in rfactor was too much though as it would be 5am (every Monday) rather then a once off. Being American with iracing, it's a bit easier since their evening is our morning. It's not ideal but it's not that bad.
I bit the bullet and signed up Friday night, 3 months $25. I haven't driven in 12 months so the first night was mainly just acclimating with it, and setting up FF for the G25 and getting used to the POS, err I mean Soltice. My best time at Laguna was 1.51. Yesterday after watching some replays and seeing that I was sliding wide too often and missing apexes, I tried some more focussed practice. The hardest thing for me is the penalty thing for going off track, even if it's just a few inches too far. Really frustrating. Finishing a time trial was impossible to get 4 clean laps at first. I finally decided to join my first race, which had 11 people and a mix of quick and slow people. I started from the back and got past alot of cars, then went into the gravel in turn one braking too late, and had to overtake them all again. Ended up with 3rd and only 4 minor incidents so not too bad. I ended up having 5 races.

Overall I had 2 2nd's, a 3rd and 2 4ths. After a few races, consistancy and avoiding those -1 offtrack penalties, things got easier. Best time is 1.49.3 but need to improve accuracy more to get it into 48's. My safety rating is now 3.41 so that's not too bad a start. Overall I am very happy.
So far..
- It doesn't have many tracks or cars that I like, but what it does have is 10/10. In this situation you can enjoy something even if you don't like that type of car, just because of how good it is made. Excellent.
- Never driven a Soltice or any of the real cars, but the tracks and force feedback are pretty amazing.
- Netcode has been very good, everything looks really smooth, and it runs well on my pc, only have had 11-12 cars at max but constant 60fps with vsync and good netcode is a really enjoyable experience.
- You can tell the goal for the graphics, it isn't about flashy shaders or smoke or sun effects, but for accuracy. Laguna is a beautiful track to drive on, especially at that moment as you are at the top of the corkscrew and the scenery opens up. Graphics are better then I expected, in terms of screenshots they look poor. In terms of practicality and the feel while driving, I think they might be better then Shift. I saw screenshots of Shift and got excited, but was very unimpressed ingame(even tho they are flashy).
- Only problem so far has been netcode where someone with a wireless connection (I think) flashes between being visible and being invisible. It's scary if you are on there tail and about to pull alongside and then they dissappear!
- With the irating and safety system, it makes some people overly cautious and overly generous. I think it would be really hard to learn your first sim through this system because it's so strict. It does teach you good habits though for the longrun. And some fierce battles can still be had! It would be really hard to go back to other public races after this though. It's like everyone drives like there are stewards or tv cameras watching. And to drive in other sims takes a different mentality. Both in being more aggressive and also trying to survive.
- It's soooo useful that you can tell the G25 to use all 900 degrees of lock and then iracing decides how much to use with each car. This is light years ahead of setting up steering locks for the momo and other sims.
- The whole internet interface, I thought I would dislike it but it's pretty good and works well.
So far so good, thanks to everyone for sharing your experience. Can't wait for some decent cars with some good aero though. I think I might like the Star Mazda's but who knows. Would it be better to renew after 3 months, or order another 12 months (making it 15 months) now? I want to drive Silverstone and it offers discounts for ordering in bulk?