ahargrove

Hello all. I am in the market, or at least think I am, for a 5 series BMW. I currently own a 2000 Ford Excursion Limited, 7.3 diesel 4x4 that I have only had for a few months. I thought with the addition of a 3rd kid I would need a massive suv and now that I have it, it's too much. My previous 2 vehicles for Ford Explorers so it's been a while since I've own a car but I'm thinking it is time again. My wife is in the market for Tahoe so that should take care of family trip issues. The BMW would be mostly used for commuting and driving when the entire family is going.
I have always appreciated the appearance and the perception of reliability of BMW and think this could be the time for me to join the club. I have been looking at 2005-2009 range 5 series with 60k plus miles because they seem to be in my price range. I understand how the series numbers coincide with the motor and realize that as you increase in series, you also get additional minor options. I am not clear on the options that come with the upper series over the lower series but that's not my main concern or the reason I have come to this forum. While doing a little research on the net in regards to the different series, I ran across some feedback to another newbie wanting to purchase a 5 series. The feedback was coming from 5 series owners that really didn't seem to have too much positive to say about the vehicle's reliability and longevity.
Since the vehicles in my price range will likely have 60-80k+ miles, this is a valid concern because I don't want my first experience to be constant problems with the vehicle. Nor do I have the resources to pay a dealership for maintenance. I am hands on and not scared to do my own maintenance or minor repairs but not looking to perform repairs on a vehicle I have just purchased. Plus I would have to listen to my wife and that is never good.
So I come to you to get feedback on the reliability of the 5 series. I like the idea of having the v-8, well just because it's a v-8 but not a must. I understand you get similar power from the turbo i-6 which would be fine but how reliable are the turbos, especially with there being 2 (unless I'm wrong about that). Is the lower model the most reliable just because it lacks turbos and has less power which would put less strain on the drive-train?
Also, I've never owned a rear wheel drive car and although I'm not opposed to it, I think I would prefer to have the awd model. With that said, how reliable is the drive-train on the x-drive models?
Sorry for the all the questions and I hope you'll can help.
Thanks in advance.