I IV and IM ketamine all the time.. It's not too intense.. it's relative.. if your tolerance is high enough it's not even that much of an experience..
Really good to potentiate trips on other psychs.. espesh mushies and when you throw in some nitrous mmm..
A good dose for me and my friends is about .3 or .5 IM.. or .2 to .3 IV depending on the feeling we want.. but tolerance seriously builds up rapid and almost seems to not go down.
We are trying to have a break this month though so that xmas/newyear can actually be enjoyed aha. 8)
Edit: I find IM and IV to be two very different experience.. IV is a like a rush of ketty color.. sometimes with 5 or 10 mins of memory blank and just feels really nice more than anything else.. depends on dose.. never lasts longer than 20 mins for me.. but im'ing last for hours and hours if you have a dose huge enough for your tolerance while IV just is a quick flash.. the cold feeling in the back of your throat is much more instant and pronounced with an IV and is ussually just the method used for an intensely pleasurable rush.
Very nice with nitrous.. so is IM though.. both interesting.. both very different.
I have done alot of both.