The Nissan XTrail model you mentioned is not sold in the United States where we are located, so I don't know much about it. I found this great blog about it however, and you might want to check it out:
Because they aren't making any more doesn't necessarily mean it's a bad idea to buy, however as the years go by, parts may become more scarce. Talk with the dealer about that concern.
Here are some reviews on the 2006 Rav4 (a bit early for reviews on the '07):
The Toyota has been getting good reviews, as they usually do. The decision will have to be up to you. I suggest you take both vehicles out for a test drive and make sure you spend a good amount of time in each to see which you truly prefer. You may want to stay within the Nissan family because you are used to it or you may decide you prefer options in the Toyota.