Hello

First off, I first researched windows about 5 years ago for my condo and now I have to do it again for our new home. I *thought* I understood windows and chose a great company, so I thought it would be easy this time around for the new home (13 windows and slider door compared against 3 windows and a slider 5 years before!).
I am now completely and utterly frustrated, because I feel like I'm too trusting with sales people, which is why I'm hoping I can get some unbiased advice (I love the idea of this board)!
Background stuff and kind of a mini-rant:When I bought my previous windows 5 years ago, the salesman had told me:
1) You don't want metal as a spacer between glass since that promotes heat loss, that's why they use a polymer spacer and is better.
2) You won't lose sill (we didn't).
So, now I'm hesitant, because he told me yesterday:
1) We use aluminum spacers for strong windows, which is good.
2) You will lose sill, no matter what you do.
- at this point, I'm now no longer trusting him, because I don't feel like I'm buying the same product. - and then he had to throw in the 'you also get a 15% discount that only applies if you buy by Sunday.'
This then brings me back to 5 years ago where he had said the same thing and then the exact same flyer with the same sale was still being passed around, so I'm now unhappy with the company that I was sure I was going to get the windows from.
I have now talked to 2 other companies and have appointments with 2 more. I feel like all the companies are giving me completely different information on what is 'good' and what is 'bad,' and I would really appreciate any advice anyone can give me so I can ask better questions for the remaining 2 companies.
Actual questions: I hope it's OK that I use actual product names? If not, then I'll edit the post and remove the names.
1) Company 1: Specializes in installation. Will install either Milgard Tuscany or Andersen 100 series. Seemed very friendly and low-pressure. Emphasized that 'install' is the most important part of windows and that's why we should go with them.
Claims. This is where I'd like to know if this is bogus or not.
Claim 1) Popping out aluminum windows with a collapser is a bad idea, which is why they remove part of the siding to remove the windows.
Question 1) Is this really true, because company 3 uses a collapser and pops windows in and out.
Claim 2) When they remove the siding, they put in 5 layers of caulking as well as flashing to ensure water will not enter the wall (in addition to window wrapping?? like a builder install). This is the proper way to install a window.
Question 2) Is this really true that this is the proper way? We would end up with a wood trim that would be needed to cover the removed siding.
Claim 3) They will do 3-4 windows at a time to ensure that the windows will be properly installed. Anything faster is at risk for bad installation.
Question 3) Is this really true that fast installs = higher risk of bad install?
Claim 4) They carry Andersen 100 series, which is the affordable version for those wanting to install Fibrex composite quality at an affordable price.
Question 4) I really like the Fibrex idea, but would I be trading in quality by going with the 100 series or is it really comparable to Vinyl windows?
Claim 5) They specifically add a wood trim around the windows to give it additional support so that the window won't just be hanging out unsupported.
Question 5) Isn't this why windows are nailed the walls directly? Why would a trim give a window support?
2) Company 2: Dealer for Andersen windows. I strongly suspect they hire out installers, so they're really selling the window, not the install.
Claim 1) There is no way non-Andersen window companies can sell Andersen windows. We would need to go through them to get quality Andersen windows.
Question 6) This really ties into question 4. He brought a series that they called series 2 and said it was the same as the 100 series, and it's crap. Opinions?
3) Company 3: Sells Procraft windows. Responsible for both windows and install.
Claim 1) We should go with them because since they do both install and the product, if there are any issues, we can call them directly and there's a warranty for life.
Question 7) Should I really be going with a company that does both so I don't run into the issue of manufacturer blaming installers and vice versa?
Question 8 ) With all these companies, The common consensus is that we will be losing sill no matter what we choose. Is that just how window install is now (because I didn't lose any sill 5 years ago)?
Sorry for the overload of questions, and thank you so much in advance to anyone who can at least answer some of these questions so I'll be less confused and be able to ask the remaining 2 company the right questions without the wrong bias.