As said earlier, for most purposes there is really no point in distinguishing gerunds and present participles, hence the term 'gerund-participle' used by some grammarians, or simply '-ing participle' by others. The most important thing is to determine the function of the word in the clause, and its category usually then becomes clear. In your example, there is a non-finite subordinate clause "the hotel being too crowded" functioning as complement to the preposition "about". The subordinate clause has a subject "the hotel" and a predicate "being too crowded". The head of a predicate is always a verb, and since "being" can be a verb, it is the only possible candidate for head, a function that we've just said can only be filled by a verb. So we've managed to identify both the function (head of the predicate) and category (verb) of the word "being" without any reference to, or knowledge of, the terms 'gerund' or 'participle'.
