Was life better in England or the Thirteen Colonies?

Comparing life in two different environments is not an exact science! Comparisons of this sort are often based more on opinion than fact. The question of whether life was better in England or the colonies very much depended on social class and situation. Let's examine this question by imagining that you are an English citizen who is offered an opportunity to move to the colonies.
If you were employed and earning a reasonable wage—unless there was a high probability that you could earn more money in the colonies—then giving up financial security would not be a smart choice from an economic perspective. However, if you were a laborer with limited skills or with a skill that could prove useful in the new world (for instance, carpentry), you might be more inclined to move. Additionally, whether or not you had a family would factor into this decision.
Life in England was not undesirable if you lived nearby a township. Therefore, it would most likely be the fact of land ownership that would factor into this decision. It is very likely that, if you were an English farmer, you probably would not have owned the land that you farmed. If you were given a guarantee that, when you moved to the colonies, you would be granted ownership of the land that you farmed, this would be an attractive incentive to leave England.
England—in comparison to the colonies—offered a vibrant city life, an economic opportunity, an educational opportunity for your family, and a degree of comfort.
If you were poor, however, the harshness of the unsettled lands in the colonies might provide a desirable alternative to the poverty of England. Impoverished citizens in England had no social or financial safety net: daily life was a struggle to survive and the quality of life was awful. There were few opportunities for economic or social mobility. Life in the colonies, on the other hand, provided some opportunity for social mobility—at least for some people.
The answer to this question therefore depends largely on the social and economic position of the individual in question (as well as other factors).