Hi Scott,
Definitely check out the FAQ that Charlieman mentions - it will be invaluable - but I thought I'd just share my thoughts on one of your more subjective questions - is it better than a real IIe.
I used to own a real enhanced IIe many many years ago and it was relatively tricked out, but no longer have that machine. Recently I started getting back into the old gear and have managed to find an LC475 and a IIe card with 5.25 drive to go with it - no real IIe however.
Just recently I got my IIe card going and my initial thoughts were "AWESOME!!" and it is indeed awesome. The LC475 is a relatively (in the retro world) modern computer that gives you lots of options for connecting with the modern age - combine that with a IIe card that gives you the best of what you might have purchased for a real IIe (RAM card, accelerator, native access to the LC's hard drive and 3.5" drive as IIe drives, mouse card, super serial card, mouse card, physical interface to IIe joysticks and 5.25" drives, display on a modern CRT and access over display modes etc) and its a hard act to beat! Certainly I would guess it would cost a lot more (and be a lot more work) these days to spec up a similar IIe. The unit itself also seems to work very nicely - most of the software I've tried works flawlessly and I really enjoy using it.
On the other hand, you notice I say "most of the software". There is some IIe software that wont run on the IIe card - I ran across one such piece during my RetroChallenge (warp6 BBS). The software I wanted to run was looking for "vertical blanking" which is present in an enhanced IIe, but not present on the IIe (despite it pretty much being an enhanced IIe). From what I can tell, there were design compromises made (probably to do with cost) that mean that the IIe card doesnt work 100% like an enhanced IIe - but its pretty darn close. Also, the display is not completely accurate with what you might have been accustomed to with a real IIe - in part because its now being displayed on a modern(ish) VGA type display which the IIe and its display modes were never designed for - dont get me wrong tho, it still looks great to me.
So whats better? Well, if I could have a real IIe spec'd out with all the mod-cons that my IIe card gives me on my LC475, I'd prefer it - but the chances are I'll never be able to get a IIe like that. I definitely prefer the IIe card over any modern emulator (even tho most emulators provide better modern world connectivity via disk images and by running on modern machines and OS's), or a modestly spec'd IIe
So the real answer - its probably going to depend mostly on you
Cheers,