I own both a tenor and baritone from Beansprout and love them both.
What I like: The instruments are very well built. They're light, resonant, and easy to play. The intonation is perfect up the neck and the tone is very clear on those high frets, which is a must when paying for a custom that is built for you. Aaron is easy to work with...he takes into account what you want and adds his insight as well. He's part artist, part musician, part woodworker/luthier, and brings all of that into the intentionality of his builds. Both are among my favorites in my collection.
What I would change: I don't know what I would change...Aaron made everything according to my specifications and also sought to make my instruments unique to me, and I appreciate that from him. I sometimes wonder if I'd prefer a spruce or cedar top instead of all myrtle, but that's because of my particular journey in discovering the sound I like. I wouldn't be surprised if I eventually got a soft top Beansprout tenor.
What I wish I knew: Beansprouts have a particular sound that's not like other ukuleles. They don't sound "Hawaiian" like a Kanile'a or KoAloha, but more folksy or bluegrass-like, which makes sense because that's the music Aaron plays. The body of the instrument is also smaller than those brands I mentioned. Be sure you understand the difference between a Beansprout sound in comparison to others you might hear from more traditional brands. I'd also ask Aaron about neck thickness and width. His standard width at the nut is 1 3/8". He custom made my neck to be wider (1.5") and thinner like a KoAloha because I prefer it that way.
I would definitely go with a Beansprout...I'll probably end up getting one more from him before my wife makes me stop the madness.
On another note, I've also bought several cutting boards and coasters from him. He's my go-to when I want to give a housewarming gift with a personal touch to it.
Let me know if you have more questions!