I'd use this idea about love to jump off into the comparison -- from feminism.eserver.org --

The poem, therefore, serves as a warning against the ultimate love. Like many of Keats' poems, including perhaps his most well known -- "Ode on a Grecian Urn" -- "La Belle" sits in the moment when conflict is crystallized. It reminds the reader that once one experiences quintessential love, all other experiences pale in comparison, and it asks the question, "Is it worth it?" The "death" of the knight and his powerful male companions, along with the desolation of nature, point directly to Keats' answer: No. For Keats, the sustained anticipation of an event is better than experiencing the event itself. Thus, "La Belle" can be read as advice from Keats to all (gender-specific) man-kind: the ultimate experience of love is not worth experiencing, for once one touches and completes that experience, there is nothing left but desolation and death.