depends
If you are looking at the best for an English speaking American who speaks little or no Spanish,l would advice Unibe.They seems to be having a lot American students coming down for their English medical programme,it's cheaper compared to the US to study in DR.
Intec dont have the English medical programme.lt is cheaper than Unibe.Medical degree earned in Intec is recognised in the US.lt is rated as one of top six Universities in DR for studying Medicine.
Your choice will depend on size of your pocket,fluency in English/Spanish,the part of US you will practice as an MD.