Extraordinarily useful nodes or interesting nodes belong on the front page. Average, run of the mill, well answered nodes don't belong on the front page. It might warrant Cat. Q&A if it is something that you feel others would use. I may have front-paged 1 or 2 things since I have been a monk. I do so with great discretion. Statistically speaking, what belongs on the front page are positive outliers in the distribution of nodes by quality/usefulness.
I had a node of mine front-paged a while back regarding EBCIDIC and COMP-3 handling. By no means am I trying to toot my own horn at all. I don't think my portion of the node was extraordinary, but the information held in that node and its replies was very useful stuff for handling a type of data that perl doesn't handle defaultly. To me nodes like that belong on the front.
XP abuse on front page nodes may happen, but it only becomes abuse when people are voting just because its on the front page, so therefore it must be "good". Otherwise, a large number of people may have just found this node useful, in which case it's not abuse, personally
anyhow... ramble off....FP with discretion ... to me that's the motto we should use.