@Federico ***************
IF you have a 6 month METV you can get almost 9 months of stay out of the visa itself.
You get it as close to when you're comin' to thailand as you can (because it starts losing validity the date it's issued).
You enter get 60 days
when that is running out you exit/re-enter get another 60 days
when that is running out you exit/re-enter get another 60 days
when the VISA is almost going to expire you exit/re-enter and get your final 60 days taking you to about 240 days (8 months)
Then you extend that last entry by 30 days at the immigration office for 1900baht taking you to almost 270 days (9 months).