There's only one MTC in the U.S., and that's in Provo, Utah, so all missionaries come out exactly the same way. And I was ward mission leader for 2 years so I went through A LOT of missionaries. LDS seminary is good ground work, but it doesn't ask deep questions, give deep answers, or do deep dives into how and why all the scriptures were written. I've done both LDS seminary (I make that distinction because there are many different seminaries) in high school, and have a degree in theology from Loyola Marymount, because I knew there was more to the story. Conversely, if you want to do a deep dive into mormon theology with a solid foundation of historical criticism, then any book by Dr. Joseph Spencer is a must read. I was lucky enough to be in his ward for a couple of years when he was the HIgh Priest teacher.