Illustrator Intensive/Workshop/Day - Worth it?

Illustrator Intensives, Illustrator workshops or just plain Illustrator Day; by whatever name they go by,  are they worth it?

They all have basically the same format with a few variations:

• You get an illustration assignment from an Art Director (sometimes you can pick your AD sometimes you can't)

• You pick your assignment and do the sketch of the spread or whatever and e-mail it by the deadline. (time given varies)

Velveteen Rabbit story By Margery Williams.
Sketch for Scene where VR  first meets the wild rabbits.
Pencil Sketch © Diana Ting Delosh

• You get feedback from your AD (anywhere from a few words to paragraphs.)

• Using your feedback, you finish your art which you bring with you the day of the event.

The Velveteen Rabbit Meets the Wild Rabbits
Ink, Watercolor and Photoshop © Diana Ting Delosh 

• Depending on the specific format of your event, your work may be:

1.  Reviewed in front of a group, along with everyone else's project. There is NO personal review or crit. You learn a lot from your fellow illustrators. You also get and inkling of your AD's tastes and their company preferences. I personally found this the least satisfying of the 3 formats.
2. Reviewed in front of the group and the AD also gives a quick individual review and also views your portfolio. The best of both worlds. You learn from your colleagues and you get some valuable face time with the AD.
3. Reviewed on an individual basis along with your portfolio. You really get a feel for whether the AD really likes your work or if you have a rapport with that person.
4. Sometimes there is an Observer option. IE: you do not do the assignment but get to be the fly on the wall. While you may be perfectly happy that you didn't stress over an assignment - there maybe better ways to spend your time/money than being an invisible non-participant at an event. 

Needless to say, I would prefer to have Group AND Individual review. BUT if I could only pick Group OR Individual, I would always pick Individual.

So, Back to my original question are they worth it?

PRO: These events give you a  a chance to show your stuff, from sketch to final, to an AD and possibly make a good connection. Gone are the days of drop-offs and portfolio reviews and it's hard to stand out as 1 postcard amongst gazillion.

CON:

1. They  can be costly. 
2. Time consuming. Some of these events are 1 day of a weekend conference.
3. Stressful. As a freelancer, no matter how well you planned, you may find it hard to give the assignment your all while in the midst of a killer deadline or 2.  I mean, Would you really turn down a gig because you signed-up to pay to do an assignment? Heck no, you need to take the gig so you can pay to do that assignment.

I have a few illustrator friends who swear by them. Personally, I can see their merits BUT I still wonder are they really really worth it.  Would I be better off working on my PB dummy and  signing up for an individual review with an AD?  I partook in 3 of these illustrator Days this year would I sign-up for another? Perhaps, if it was with an AD/publisher I was really interested in.