I've been in the Guard about 2-1/2 years. I'm currently in transition, about to start my first year of residency.
1) do you have any regrets and why?
I have
micro-regrets, but not
macro-regrets. By this I mean that there are days I wish I hadn't joined, but never weeks I wish I hadn't or months I wish I hadn't.
There are some weekends that I just don't want to drill. With Flexi-Training, if I have a real academic conflict, I don't drill. But more often there's just something really cool happening (ski trip, buddy in town, etc.) that I'd much rather do than drill. These are micro-regrets.
But overall it hasn't been a big conflict with medical school. Many medical students have absolutely no conflicts with medical school and can devote everything they have to it. The Guard is a small conflict. Less a conflict than a marriage and much less a conflict than a child, but more a conflict than intramural volleyball or an addiction to Game of Thrones.
So no overall regrets, but, sure, there are times that I'd rather not drill. It will be interesting to see if my perspective changes as I start residency. In a few weeks. Gulp. Because I'll be an actual physician, which gives a bit more possibility for responsibility and an actual assignment in the Guard. The
Flexi- part of Flexi-training may diminish.
2) is there anything you found out after joining that you wish you would have known before joining?
That I
really don't like the beret...
No, seriously, I did a lot of research into my decision to join and made sure I was at peace with it. I read a lot of this forum (this thread was particularly helpful) and contacted individual Guardsmen who were very patient in answering my million and one questions. So there were no big surprises along the way.
I suppose the only thing I wished I'd known before joining (and it wouldn't have affected my decision any) is that dealing with the Army on all things
administrative requires a lot of patience. There is a lot of check boxes to be hit and online training to do and "urgent" requirements to get dental clearance within five days and the like. These can be aggravating, but it's the price you pay. There are similar frustrations dealing with any big bureaucracy, but the Army is different in that these are not requests, they are
requirements.
I suppose another thing I'd wished I'd known, just for comfort's sake, is that the Army Medical Corps is a lot more
diverse than I was expecting. I'm a non-traditional Guardsman in many ways. For one example, my political leanings are much more to the left than your average soldier. I was happily surprised to find that while the Army as a whole very much trends towards Republican and Christian (evangelical, at that), AMEDD is probably more representative of the country at large. That was nice to find.
3) what are the cons for joining?
It differs as a non-deployable medical student/resident vs. deployable attending.
As
medical student and
resident, you need to come to terms with the fact that you are releasing a part of the total ownership you've had over your entire life. There are things you now "ask" rather than "do," which is a culture shift that can be uncomfortable. I think it's somewhat analogous to getting married, in that regard.
If you have any tendencies to experiment with drugs, you need to come to terms with the fact that that is now
over. The Army will come down on you like the wrath of God and it can be a career-ender on your civilian side as well. If you still want to toy with drugs of any kind other than ETOH and tobacco,
do not join.
You also need to realistic about your time and be prepared to devote one weekend every month.
Do not visualize Flexi-Training as meaning you will drill once every quarter; visualize it as meaning that you will drill every month but you have a safety net for exceptions. Some of the application of drill and Flexi-Training may vary by location, and many places are very loose about drill, but the rules are federal. One change in command and your world may change. Moving for residency can mean moving from an essentially no-drill state to one in which you're expected to show up in PT gear at 0600 first Saturday of the month. So be prepared to make that commitment or don't join.
For beyond residency, the biggest con of Guard service that I had to come to terms with was the fact that I will be limiting my professional opportunities for as long as I'm in the Guard. I can't start a solo practice, obviously. I can not, in good conscience, join a small private practice, as a deployment would be crippling to my colleagues. I'll need to limit myself to larger employers due to deployments. That's a bother to me, but I've decided to see how it goes and if I find it too professionally distasteful, I can resign after a few years of service as an attending.
I think the decision to join the Guard really boils down to whether or not you're ready to be a
soldier. Forget the programs, forget the Flexi-Training, forget the rest of it. Ask yourself:
Am I ready to be a soldier? If you're not, and the occasional sacrifices, discomfort, and inconveniences that it entails, joining the Army in any context has the potential to be a decision you'll have great regret about. If you are ready to be a soldier, you'll be making a
very small sacrifice in comparison to most of your fellow soldiers and your ultimate goal will be to keep these men and women healthy. If that isn't something that would make you proud, don't join.
You just said the same thing I did. We are saying the same things, it just seems youre getting a little caught up in the semantics of how I said it. Im trying not to use military speak to be as clear as possible about what one can expect. When I said special status that would include your 00E67 mos. 
