I heard (on this forum i think) that joining the Temple is very good cause they give you very uber items [img]smile.gif[/img] Does it have any disadvantages? What very good items will they give you?

I don't think you get more good items than from other guilds/houses. You will get Ebony Mail - a very good piece of armor, which you cannot get otherwise.
At any rate, try the Temple. You will get new quests, some of them very nice.

You'll get free healing/boost/cure various status if you touch a temple shrine. You can also get to sample some good items ( swords/armour/etc etc ). When I say sample usually it means when you found it you have to return it. ;)

You can get back most of your findings when your rank becomes enough high.

downside: most walking distance of any quests in the game... you gotta go a LONG way for some of their quests.