Kerwin, just finished my IR at Sunstate (sunstateviation.com). Recent Cessna 172S with garmin G1000 and close to major FL attractions. It took me about 70 hours flight+simulator and about 8 weeks in total to get it done. I had about 200 hours VFR day only with poor radio skills and was not really prepared. It took me about 7 weeks in total. Had to get current on the plane, garmin 1000, IMC conditions, night and cross country time, IR theory... Everything depends on your level and preparation before the training. But if you want to get it done in 4 weeks part time, you better be well prepared beforehand.
The weather was OK but during the 40 hours in the plane, I got about 15 hours of real IFR. And real IFR is a totally different ballgame than being just under the hood. Getting the instructor shutting down the PFD with leaving a partial panel and the MFD for VOR/DME infos during my pre-checkride when the clouds bottom were just above the minimum of the approach makes you fell how well you are ready :-)
Jacques.
One thing I should add: if you are an aircraft owner, or plan to buy something, then if possible try to train in something similar.
I intentionally chose (in 2006) a school which did not have G1000 equipped planes, because mine isn't and I wanted to get the most out of the training.
I would think finding a non-G1000 school in the USA must be getting harder every year.
Currency on type is almost everything in flying 
Also, don't bank on it being a holiday. It's hard work. In the 2 weeks I had, I was shagged every day. In the two spare days I had, I met a friend (who drove up) and had a walk around Phoenix; that was it.
I also did everything in one go and would recommend that. Definitely do the written beforehand if you do an intensive course. There's quite enough to do without the written stuff on top. I chose California and took 14 days. That was to do both a PPL and IR. I had the CFII full time on a one to one basis, which was great. We had no rest days, which meant I was very tired by the end of it. Six days a week would have been better.
I needed the PPL as I had only a UK NPPL, so couldn't get a piggy back PPL (although that's not necessarily a good idea anyway, as others have pointed out). The PPL manoevres are a bit different to how they're done in the UK, at least in my experience. There were more of them and some of those that were apparently the same, were harder in the requirements for the FAA (notably slow flight and stalls).
I found the IR training very hard, 8 hours a day (plus homework). Some days, after another approach that had gone full scale deflection, I was thinking that this IFR flying really wasn't for me. My wife came along for a holiday but actually the moral support was great to have.
If you have a tight schedule, make sure you're based at somewhere with an ILS. The only IAP at my base was GPS and we lost 2 days being unable to get back in.
However you do it, try to have a conversation with the instructor you'll be using in advance. As part of the trip we flew out of Telluride, the highest commercial airport in the US, in solid IMC. It happened to be "partial panel" day, where the whole day was flown on partial panel. Threading between the mountains the instructor commented how some he knows won't do IFR training in IMC at all, let alone partial panel in the mountains on oxygen in IMC.
Another advantage of going on a trip is that you don't fly the same approach twice. The basic pattern we used was to do an IFR departure, fly to somewhere else and do their approach but "miss", then fly to the next airfield, do the approach to land, switch pilots and do the same thing at the next two airfields enroute. This means you get to do all kinds of different approaches. Some people prefer to just do the ILS at Southend over and over and over, almost by rote, which is okay for passing a test (assuming you do your test there too!) but less good when it comes to actually using your new IR.
I'll shut up about it now, lest I sound like an advert.
David said:
As part of the trip we flew out of Telluride, the highest commercial airport in the US, in solid IMC. It happened to be "partial panel" day, where the whole day was flown on partial panel. Threading between the mountains the instructor commented how some he knows won't do IFR training in IMC at all, let alone partial panel in the mountains on oxygen in IMC.
*(: De gustibus non est disputandum :)*
Thanks you all for your answers. Great suggestions.
TJ said:
make sure you're based at somewhere with an ILS
To expand on this, has anyone other recommendations on what one should look for when looking for a base airport ?
ILS or LPV with c.200ft minima.
The IR PTS (Practical Test Standards) specifies what are the special emphasis areas and the TASKS to successfully demonstrate during the checkride. http://www.faa.gov/trainingtesting/testing/airmen/teststandards/media/faa-s-8081-4e.pdf
Typically the checkride will consist of a hold and 3 approaches (some on partial panel), one VOR, one GPS based and an ILS. So better to be based at an airport with different approaches or have these in nearby airports. Also the quality of the training will be higher if you can fly many different types of approaches: e.g. a VOR/DME is pretty different than a VOR with a procedure turn. So a busy area with plenty of airports with different approaches makes it more efficient.
Peter: "This forum is getting way too intellectual. I had to google on that one."
but as you mentioned before you had already passed your Dr.ndb ...
