Hi Groome, I'm a member at EL and have been for approx 3 years.
First off: there is no more crossing a 4-lane road! A bridge has been built a couple of years ago. I'll try and address your questions:
moving down to Sydney and looking for an affordable club. Eastlake GC looks to fit what I'm after? Any ideas or recommendations please ?
Yes EL GC is the most affordable Sydney course you will find. However I'd invite you to call other similar clubs in the neighbourhood: Moore Park, The Coast, Randwick GC (a goat's track IMO), Kogarah, possibly St Michaels, and Bonnie Dune next door to El. Although Bonnie did go private last year.
you will find that most have joining fees ( I beleive that EL do not) and have higher subs. While some tracks are considerably better (thinking of St Michaels and Bonnie Dune), Eastlake is a very good test of golf. In superb conditions.
How would you rank the golf course compared to others in the area?
I'd rank it something along the lines of:
1. St Michaels
2. Bonnie Dune
3. EastLake
4. The Coast
5. Kogarah
5. Moore Park (I've never been a fan of this course)
6. Randwick
Of course I may be biased 
but I have played all of these courses many times.
Is it usually in good condition?
This is where EL has a massive advantage. It is nearly ALWAYS in prime condition. At least it has been in the last 2-3 years that a new green keeper came in. he has turned the course around. The big advantage we have is access to a LOT of water, that means that fairways are lush all year round (even in summer when a lot of courses burn up quite a bit). The greens have gotten faster over the years and most being elevated can make for a very touch course when they have been rolled and cut recently. Rough, bunkers and cart paths leave areas for improvement no doubt.
Is it a good golfing challenge?
yes yes and yes. It definitely is. I've been low-mid single figures for years, currently off 2 and have never shot to par in comp here. While the course is not long, it is relatively tight, and getting into the trees can mean an automatic bogey. There is water in play on most holes and at least 5 have very real OB to take into consideration. Like most courses, there are some cracking holes (6, 8, 9, 13) and some less so, some reachable par 5s, some not. The only gripe I really have with the layout is that the par 3s are generally too hard (from the plates). So yes it is a tough golfing challenge, and friends from the club agree that the h'cap you get at EL is easily exportable to other clubs.
How fast are the average competition rounds ?
I tend to play early (off before 8) on Saturdays. Because of the early start that means that I'm usually round in 4 hours. While that may sound like a lot it's not bad considering the massive bridge (see above) you have to cross twice!
Also, what is the general social vibe and atmosphere at the club?
It's good. It's not posh-private and quite down to earth. Like ALL clubs out there, most guys are good guys but you will find the occasional d**khead. members are always up for a beer or two after the round to shoot the ****.
I'm looking to join with my 14 year old son , my wife doesn't play - but may be enticed ?
Not too sure about this, but I know that there are some junior clinics on the week-ends. This tends to be for younger kids. I do think they have a program for juniors, but I'd highly encourage you to call the pro-shop and ask. As for the wife, well my wife was a member there for a while, but to be honest the lady membership is absolutely tiny. In large part it's due to the fact that the course is LOOOOONG to walk (with that damn bridge) and will take it out of you. It is a tough track for the ladies. I don't think they have more than 20 or so lady members there? Unsure.
Anyway, I couldnt recommend it highly enough if you're a Syndey-Sider. It's very accessible being near Randwick, the best value for money in Sydney, and a great challenge!
Cheers
