Hi Monu,
yes you're right, this is the last week of this years Oktoberfest. You can find some pictures and facts on the official homepage:
Oktoberfest
To your queston: yes, I've been there twice - but I live only 100 km away and the two visits were somewhen in the last 15 years. What's really strange, because everytime I've been there I really enjoyed it, the atmosphere, the people and - of course - the beer.
If you expect sensational rides you may be disappointed, there are some, but just the average choice like on any larger fair.. An additional downside is that especially on weekends it tends to be very crowded and it may be very hard to find a seat in a beer tent (or more likely beer hall -they are huge). And if you're alone you're likely loose your place when you've to go to the toilet.
And for me an additional problem is that I have to get home somehow..
So if you really want to visit the Oktoberfest I would suggest to bring some friends, rent a room in the range of the public transport of Munich and start your Wies'n experience on a working day (Monday to Friday) in the early afternoon.
John