It was mentioned in a thread *way*way* down there that JT's loss for words in this little speech appears that he might actually have some real feelings for Catherine. While I've never read it that way, I can see how it could be read that way.

However, I don't think he has a loss for words; he - for once - is actually able to put a filter on his mouth and doesn't say the words that he is thinking. Here's my reading of this speech:

“That is kind of you, however — kind and good–natured. I shall not forget it in a hurry. But you have more good nature and all that, than anybody living, I believe. A monstrous deal of good nature, and it is not only good nature, but you have so much [money], so much of everything [- Lord knows I want more of everything]; and then you have such [an inheritance to look forward to from Mr. Allen] — upon my soul, I do not know anybody like you. [If I marry you, I get to control all your money and a good natured wife into the bargain. What say you? Shall we shack up?]” (Ch. 15)