For a textual answer to your question you could look at what both Laertes and Polonius say to Ophelia in Act 1 of the play. Laertes and Ophelia have an interesting conversation right before Laertes plans to go back to school. As the attentive and loving big brother, Laertes asks Ophelia about her relationship with Hamlet, and tells her that he thinks that, while Hamlet may express that he loves her, she shouldn't take him too seriously. He warns her to
Hold it a fashion, and a toy in blood; . . .
Forward, not permanent -- sweet, not lasting.
When Ophelia questions that assumption, Laertes gives her a very solid assessment of the situation. He explains that, as a prince, Hamlet is not as free as other men are to choose their mates. He's right when he says
Perhaps he loves you now,
And now no soil nor cautel doth besmirch
The virtue of his will; but you must fear,
His greatness weighed, his will is not his own,
For he himself is subject to his birth. . . .
for on his choice [of wife ]depends
The safety and heath of his whole state [Denmark]
Generally, princes marry princesses for social or political gain. Ophelia is not a princess. Hamlet may have true love for Ophelia, but that doesn't guarentee that he can choose her as his wife. He cautions her to not lose her honor to Hamlet and lose her heart and her reputation. Given these ideas, it would not seem that Hamlet and Ophelia are not a good match.
On the other hand, Ophelia expresses genuine affection for Hamlet and defends Hamlet and their relationship when her father has a similiar conversation with her about Hamlet. Polonius isn't as diplomatic about Hamlet's motives, suggesting something a bit more base, but his point is still the same. Hamlet is a prince, and as such, lives a very different life, with very different expectations.
There is textual evidence that Ophelia thinks highly of Hamlet and that she is legitimately concerned over the apparent madness of Hamlet as it is displayed later in the play. Consider her prayers in Act 3 when Hamlet is berating her in the "get thee to a nunnery scene. She is so devastated by his killing her father and his rejection of her that she loses her sanity and ends up killing herself. Her feelings for Hamlet are true, and as evidenced by Hamlet's reaction to her death in Act 5 his are as well, but the circumstances of their lives in the time frame of this play strain the relationship beyond its endurance.