SDFlySurf,
Congrats on the license and the plane.
When I bought my M20J in December 2017, I had 270 hours on a 30-year old license, 100 of which was recent in a Cessna 172. I had two hours in a Mooney, including a demo flight with a guy on this forum and a 1.5 hour orientation lesson in a J Model operated by Pinnacle Aviation at KCRQ. The broker I bought the plane through in Texas set me up with a really great guy who had done transition training for the Mooney factory.
So I went to San Antonio in December with three days blocked out for the training (cost was $350/day for the instructor). I had read all the manuals, etc., in advance. We did an hour or two of ground work on Day 1 then flew for 4.2 hours, 11 landings and a good barbecue lunch in Llano. At the end of that first day, a Wednesday, the instructor said, "Well, we should be done by noon tomorrow, so you can get up to Dallas ahead of the weather." (I was going to meet my wife at my in-laws for Christmas in the Dallas area, and there was a cold front headed south that was going to hit on Friday.)
On Thursday, we flew for 2.9 hours and 11 landings. We landed back at Kestrel by lunch, and Bob says, "Everything looks good. How do you feel?" I felt fine. But I thought there surely must be some kind of rule against Brent jumping into a Mooney and flying off by himself to wherever he felt like going. Nope. Filed a flight plan, got in the plane without asking anyone for permission, and flew to Grand Prairie. Go figure.
Anyway, to answer the question: for me it was 8.6 hours of transition training, including the 1.5 at KCRQ. I had to fly 10 hours dual, and 5 hours solo for insurance. I'm really enjoying the plane and figure I should have decent technique and a handle on the settings after, oh, 500-600 hours, max....
Enjoy.