Article II - Last I was there, over a year ago, you could shoot rifles on their indoor ranges. Once again, please keep in mind that my opinion and information on Article II is over a year old. Maybe things have changed since then. I don't shoot there anymore. Last I was there the ranges were 25 yard ranges, shared with rifle, pistol, shotgun (slugs only) or whatever people wanted to shoot. The ranges were loud (All ranges are loud but these were extra loud due to the guys with rifles, some with comps or brakes, mixed on the line with the pistols). Make sure you have adequate ear-pro and double up. The ranges were also very smokey. I'd literally have to clean the black gunk out of my nose after shooting there a while. The staff could also be pretty rude. Personally, they were nice to me, but they really yelled at some folks. Making a mistake on the line is one thing, but new shooters don't learn a damned thing when people yell at them. It just makes them nervous and more likely to make more mistakes. On the other hand, In defense of the staff there, the place tended to attract alot of people that...well...lets just say they weren't the safest or most experienced people in the world. I suppose that after you've had to talk to people over safety issues multiple times, and been flagged multiple times, one tends to lose their temper. Last I was there the place was really busy all the time. Parking was tough to find and you'd have to wait in line to get a lane...either that...or phone first in advance to make a reservation.
GAT - They've got some indoor rifle ranges there. I believe a 50 yard and a 75 yard. I've never shot on the GAT indoor rifle ranges but I've heard they are nice. The pistol ranges have been nice, the staff has always been courteous and helpful to me and my wife, and I've taken a couple classes there too.
ASC - Its hard to beat ASC if you plan to do alot of shooting. There is a covered pistol bay. Then several uncovered 50 foot pistol bays, 25 yard rifle bays, a 50 yard range, a 100 yard range, a 200 yard range, and a 600 yard range. Shooting Steel is allowed as long as its commercial manufacturer and you bring documentation to prove that its commercial manufacture and being used per the manufacturers instructions. Shooting on the move is allowed. Drawing from the holster is allowed if you have a sign off on your membership card for it. Same goes for shooting at 600 yards, you can only shoot at 600 if you have a sign off on your membership card (However you can still use the 600 yard range if the firing line is moved up to 200). In other words, the ASC offers alot of stuff you're not going to find anywhere else nearby outside of private land.
As far as being intimidated, you would likely find yourself less intimidated at ASC because everyone is a paying member. Its a club. People are largely friendly and just love to talk about, share, and enjoy shooting.
The downside is, as was mentioned. Price. Its very expensive. No getting around it. There is a yearly member due, plus a monthly fee they charge that is flexible for a given year, plus 5 hours of volunteer work on the range (or 10 hours if you are in your first year) - however, you can also "buy out" those hours if you don't have the time to volunteer. All in all it will cost you between $500-$600 a year most likely.
The other downside is range availability and that really depends on what you'd want to do if you joined. Individual ranges and bays are "rented out" to law enforcement for training and to some select club approved private training companies. So during those times, those ranges are closed to members. Also, there are often activities and the ranges are closed for general shooting while the activity is going on. Things like Appleseeds or Practical Rifle or 3-Gun competitions or CMP events or IDPA, etc. etc.. The club tries to keep ranges open to the general membership as well but this is always a subject of some strife. Some folks love taking part in the activities and don't mind the club making money by renting out some ranges because the money gets spent on improving the club. Other folks are members who just want to use the ranges to shoot and get angry when the ranges they want to use are closed on a weekend for activities, or during the week they take a day off and the range they want to use is being rented to law enforcement.
If you are interested in ASC, you should go to their website...
http://www.aurorasc.org/
On the home page you'll see the calendar. Scroll through it and see if the availability of the ranges bothers you and you feel that the ranges you'd be interested in are available at the times and days you'd most likely shoot. Scroll through it to see if the activities and events there interest you.
You can read about the facilities available, membership, etc.
Also, you might see mention of the Zombie Shoot. Thats an "Open to the Public", paid admission event they hold every year. Its in mid-september this year I believe. I've been to it a few times and its alot of fun. It kind of reminds me of a kids fun fair for grown ups that love shooting ;) Its all tongue-in-cheek and a good time. It also gives you a chance to come out and see the club, and form your own opinion.
Buffalo Range - This was already mentioned. I've haven't been out there since the late 90's and it was always alot of fun. Every time I went out there I was determined to "get something done" but I never seemed to leave the plinking pit. I'd always be having too much fun shooting various junk...then eventually lose track of time and get heat sick
Good fun though.
Well, thats the shooting I'm familiar with in the area. Hope this was helpful.