A really good agent is interested in my book - need advice!

A really good agent is interested in my book - other agents might be offering early next week; could use agent selection advice, timing advice, etiquette advice, anything advice!

I published a very popular article with an attached book, got publisher interest, and used the publisher interest to generate agent interest. Several pretty powerful agents have requested my proposal and one of them said yes immediately.

She seems absolutely wonderful, and an expert in the niche of my current book, but a lot of the remaining agents who may contact me next week are technically bigger fish. I could use as much advice as any of you have to give.

I have a phone appointment with the currently interested agent early next week, and I am currently planning on hearing her out in terms of her plans, hearing anyone else out that offers during the week, and making a final decision on Friday. Is that reasonable and/or wise? I don't want the interested agent to feel like I'm dicking her around and holding out for someone 'better', since I really do like her, but I also don't want to move too quickly on what is a pretty huge decision.

Thanks in advance!