Twisted. I think I can agree with pretty much everything that you are saying.
I also love the SC series and although it may have been inspired by Metal Gear it really is a different animal. SC is all about travelling from point A to point B and doing it as perfectly as you possibly can, the story is generally a side issue.
The MGS series has always been more of a cinematic experience with great depth and research going in to the story and place setting.
I wuld have to say that I generally enjoy the SC games much more than MGS but MGS: Twin Snakes on the GC was just fantastic for me. All of the story and surroundings of the first game of the new series with the engine of MGS2. Brilliant.
Going back though, if I was asked to choose I wouldn't be able to. I look at them in totally different ways.
Also, the MGS series actualluy pre-dates the SC series by 15 years. The first title was released in 1987 on the MSX2 and later NES.
Below is the full list of titles right up to MGS4.
* Metal Gear (MSX2/Famicom/NES/C64/PC/Mobile Phone/PlayStation 2, 1987)
* Metal Gear 2: Solid Snake (MSX2/Mobile Phone/PlayStation 2, 1990)
* Metal Gear Solid (PlayStation, 1998)
* Metal Gear Solid 2: Sons of Liberty (PlayStation 2, 2001)
* Metal Gear Solid 3: Snake Eater (PlayStation 2, 2004)
* Metal Gear Solid: Portable Ops (PlayStation Portable, 2006)
* Metal Gear Solid 4: Guns of the Patriots (PlayStation 3, 2007)