Meme are extremely powerful when made with a good blueprint. They can destroy metal stone wood and thatch so if you are on pvp I recommend you have one of these to clear spam/destroy base. They can also have modules attached to them that can be a forcefild or rockect launcher. If cryopoded the module is damaged. Also the module can be damaged if you take if off. So avoid cryoing and taking off the module.
*WARNING* Keep Element on meks at all times! As long as your mek is out you must have element on it otherwise it will despawn/die. 1 Element per day it is out seems to be enough. I've lost 2 meks with no trace even in tribe log because of this.
Do not fight a level 290 corrupt wyvern with a level 51 primitive Mek. Let's just say they self destruct. 40 element plus other mats just exploded. Thank God for glider suite, that shit blasts you straight into the air when it explodes. Still died wyvern got me on foot. Fml.