Not that this a state I attain very frequently :P
There are certain breath techniques that will land you in the clouds. If you do a practice like that without proper grounding, you are likely to be very disconnected from physical reality. That's my opinion and personal experience. In general (and they have the science to back this up) it heightens awareness of your senses. Though people who meditate have higher pain tolerance -- not because they feel less (since they feel more) -- because they have developed willpower to not react to stimulus the same way. Super fascinating!
Many teachings of meditation also incorporate teachings on compassion and self love which are sorely lacking in modern workplace.
I received so much from meditation (and ayahuasca) retreats it led me to co-found Retreat Guru. http://retreat.guru. Our mission is to get more people on authentic retreats.
Bad technique can lead to problems like depersonalization, and people can get something like an addiction to jhanas - but as far as I know elite meditators simply get more and more "enlightened". In some cases this may lead them to join a monastery or become a hermit, but whether this is problematic depends on your point of view.
I meditate between 1-2 hours a day. Sometimes I will do more and sometimes less. I find it saves me more time that it costs. I get distracted less, I need less sleep and I find myself in the right place at the right time more often. I also have more clarity on what is important so the time I have, I use wisely.