Suntower, what you were thinking about the extended libraries giving you the all the articulations of the full libraries relates to the download libraries, not SE or SE Plus.
As Cyril said, the SE and SE Plus extended libraries add articulations to the instruments that are in the standard SE and SE Plus libraries. If going with the SE series, it is helpful long-term to plan on purchasing all four of the libraries. The essential basics are covered in SE Standard. The additional articulates for the SE Standard library, found in the SE Plus library are also very helpful, and truly do round out what is in the Standard library.
As for a VSL and EWQLSO comparison, what is best depends on what you are after. EW is easier to use out of the box (if you could eventually add MIR or MIR SE for VSL, the advantage swings strongly in VSL's favor). Similarly to Cyril, I stared with with EWQL, finally moved to VSL, and have never looked back. Unlike Play, VSL's programming is fabulous, giving you complete control and the ability to create and customize each instrument as you see fit. You can also set up matrices in VSL with consistent keyswitches (every instrument in EWQLSO has unique keyswitches).
Also, with EWQLSO, to have any flexibility at all in terms of style, you would have to also get the close mics. The basic EWQL sound is awash in reverb - great for "Hollywood," terrible for chamber music, etc. As a one-time orchestral musician (though not professional), to my ear, VSL gets the closest to the sound of an actual symphony orchestra. For example, as a bass player for many years, the variety of articulations of the solo bass in the solo strings library come the closest to what I can actually do with a bow (the solo strings in SE are also very usable).
If all you are interested in is "Hollywood" (you didn't describe your intended use) you will likely be ok with EW. However, you mentioned that you liked the sound of VSL better (as do I). I would strongly suggest that if you can't quite yet afford VSL, that you wait, save up a bit more, and then buy VSL. In the long run, spending money on samples that you do not really like as much is not going to be cost effective. What could very well happen is that you will buy EW, wish you had bought VSL SE, start saving up for the VSL SE libraries, get them, and then rarely use EW. In that case, IMO, better to start with VSL in the first place, and add to your collection as you can afford to do so.
Edit: I should add that high-end pro users (not myself) tend to eventually buy most of the major commercial libraries available and mix and match on a per project basis. However, especially when starting out, and/or when funds are limited there are also advantages to getting to know one particular company's libraries very well. It is all too easy to end up spending $$$ on all sorts of libraries without ever mastering any of them.
