Welcome to our forum.
Well... I'd say go with your gut. If you can afford to lose a couple hundred bucks and the other dealer has something in your price range that you like... I'd go for it. I bought used and have no dealer, but am a firm believer in doing business with someone you like and trust. You better believe I will never do business at Honda Cars of Corona ever again. They don't even get my routine maintenance cause they pissed me off. They treated me like crap after I dropped 30k on a car. I now drive 30 miles away now to get my routine maintenance done. (And people {you know who you are}please don't bash me for owning a Honda )Edited because I got off track...Anyway, with regard to the tact part.. I would just say you changed your mind. If they push for details say you found another tub that you liked better (fit your needs, etc.). I probably wouldn't say that you liked the other dealer better, but nothing wrong with saying you found a tub you liked better.
One word of caution about the new dealer: Over the years I have learned to be wary of enterprises that have kids, especially infants, where business is conducted. It is okay to be dedicated to your kids, but allowing them to interfere during business hours shows where the customer stands on the priority list. If it happens before the sale you know what to expect after the sale.Other than that, the new dealer sounds like good people.