Sure in SL you can completely customise every single aspect of the game. But to actualy make something advanced (to use or to sell), you need a $400 program!!!! And you must be tech. or atleast code expert to make scripts for the objects to work, which I am not and it is pretty hard for me to make something.
To own a home you must have a paying subscription, and then pay an additinal monthly fee if you want to upgrade from the free size lot.
Then if you dont want to play on the Teen server you need to deal with the thousands of pronographic content that is uploaded and spamed around the game before its taken off. And deal with some horrifying obscene content chasing & sticking to your avatar when you try to go to a sandbox and create something.
To make any large amounts Lindens you have to put in real money. Of course you can make money off the game too... .
The graphics are alright, they are not superb nor are they horrible, but they are alright. Not as good compared to other MMORPGs.
There is constant lag and crashes in SL. (My comp has runs 3.4 ghz, broadband internet, over 4GB ram, and i have over 300 GB space left on my comp, a $400 nvidia video card the name of it I cannot remember and a fairly execeptional sound card, its a very good and fast computer) and yet I still suffer lag and crashes on SL when I try to fly me and my friends on the Jet I bought from another player.
In my opinion, SL is a great short term replacement for TSO and boredom, but it is not a very good game (in my opinion, others will argue otherwise) and I enjoy it only for the ability to fly planes and nothing else, I would give it a 4/10.