O.K.,
Not trying to be a troll, I plead complete ignorance in advance.

But I am wondering if someone can tell me why an EoTech, Aimpoint, etc. is so superior to other optics??
For example, I bought a BSA red dot scope at wally world for approximately $25, it shines a pretty red dot on a clean clear lens.
It looks like a pretty cool unit, granted I have not shot with it yet. I got it mainly to play around with, but when doing some beaver removal at night, I realized that I can't see my front sight even under the full moon, so I am thinking of mounting a red dot cause it'll be usefull for low light conditions.
Anyway, what are the measureable differences between the expensive optics and el cheapo's. I have always been an "iron sight" kinda person and don't know much about optics. I took the scope off my Remington 700 BDL .30-06, cause I am just more comfortable with open sights.
Anyway, I know that they are used by the govt. etc. but was wondering if there were any obvious differences that I didn't know about.

Thanks!

The difference is quality which translates to reliability.

The cheaper optics tend to fall apart under heavy use and harsh conditions.  A lot of folks who shoot only at the range can use a $30 BSA red dot for years and get good service from it.  Drop it a few times, get it muddy and wet, and it's probably not gonna hold up anywhere near as long.  

EoTechs and Aimoints are designed for combat...quite simply, a lot of folks who use them are putting their life on the line, and need something that's gonna work every time when the shit hits the fan.  I've used a BSA red dot myself, but I sure wouldn't bet my life on one.  For starters, EoTechs and Aimoints are waterproof to a depth of, well, if you're in water THAT deep, you got bigger problems hehe.  They're also much more shock proof...the EoTech for example has that nice protective hood around it, and Aimpoints are pretty rugged...I knocked over one of my rifles with an aimpoint on it, and it hit the concrete floor pretty hard.  Other than a gouge in the metal, it showed no signs of not working.  

For magnified scopes, the differnces are much more pronounced.  Cheaper scopes tend to have glass that is not as clear or as bright, and can be "fuzzy" around the edges, or have a *very* small area within the field of view that's actually in focus.  The windage/elevation adjustment won't be as precise, and may feel mushy or otherwise not as good as in a better scope.  Also, you won't get the same degree of waterproofing, and the scope may actually cloud up in humid whether, the reticles can break, etc.  

You *do* get what you pay for in scopes...but having said that, there ARE bargains out there...I've stumbled on a few pretty good pieces of glass for not a whole lot of money.  

For a *decent* low budget scope, you're still looking at $100 or so on the low end, although some folks here have taken a shine to the Simmons Pro Diamond scopes, and they're only around $60.  

You will have an epiphany when you look through your first good scope...for me, it was a Weaver Grand Slam that I bought for my .22-250.  I was amazed how bright/clear the image was, how precise the clicks were, how great the scope was to shoot with.  

I have bought a lot of guns over the last 5 years, and because I'm an old geezer w/ bad eyes, I usually slap some sort of optics on everything.  I'm currently upgrading a lot of stuff...now, I'll never have the budget in this lifetime to go Schmidt and Bender on everything, but you don't *have* to spend that kind of money go get a really nice piece of glass.  

when the time comes to buy something, let me/others here know...you'll get a lot of good advice re specific shooting needs/budget.  

Quoted: For starters, EoTechs and Aimoints are waterproof to a depth of, well, if you're in water THAT deep, you got bigger problems hehe.

Cool, then they can be used for underwater bumpfiring!!!
I know I must gets one now!!

But seriously, thanks for the info. I have never personally looked through one of the EoTechs or other nice optics, but I will have to check them out at the next gun show.
I can definately see an advantage to them for quick target acquisition, etc.
I may just have to save my shillings and pick one up (after I finish my A4orgery)

Darned Black Rifle Disease!!  

my eotech is also NVG compatible

I agree with Fenian wholeheartedly. You do indeed(in most cases) get what you pay for.  But for just plinking or beaver hunting (sounds funny!) I would probably not spend $300+ on a red dot sight.  One other thing that is way cool about the EOTech and Aimpoint is they are both parallax free. Hope this helped!