Will 14.04 be good for install just after release or shall I wait few months for it's revision?
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That's up to you. That's the reason this question has been tagged as opinion-based: it depends on your individual needs.
If you can afford to wait a few months, then there's no reason you need to upgrade immediately. Support from the previous version won't run out immediately. This therefore gives you an element of choice.
On other other hand, as soon as Ubuntu 14.04 is officially declared as "released" it is supposed to be considered fit for release and to be used from that point. So there's no reason you should need to wait any length of time after release to get a release-ready product.
So your choice.