I have seen quite a few indications in several posts that "your equipment may change", however, this has not been my experience so far (ie. I book PTY-IAD/BWI on a Max 9 and always get the equipment I booked).

I am starting more travel to South America where Copa makes more sense schedule wise but want to get a sense of how often these equipment changes happen, particularly from Max 9 to non-dreams equipment.

My alternative is flying Delta to GRU/EZE/SCL where I can have either Delta One Suites or at a minimum Delta One and then connect to LATAM if needed, but this makes my trip longer.

From my own experience, it depends heavily on the route. Most equipment swaps I've had are on shorter flights like GYE or MIA. It's always a MAX when flying to LAX, SFO, EZE. Seems like they prioritize equipment for those routes.
It also seems that equipment swaps tend to downgrade, never upgrade.

Yes they definitely prioritize the MAX9�s to LAX and SFO. But you really have to watch the frequencies on PTY-GRU/SCL/EZE as that�s a lotto as far as equipment changes. Some will go your way and others won�t.

Thanks.

As I mentioned on my original post, I am lucky that I always get them when I book them to IAD/BWI and even to SDQ. But then there's the random scheduling where the same flight has a different equipment depending on the day, not even the day of the week but just randomly throughout the month (ie. ASU, SCL, and the two routes mentioned above on a given Sunday have a MAX9 and then another Sunday a 738)

Copa make an announcement that they are only gonna use max 9 to EZE. Therefore a guarantee dream business class. Also, to GYE, in all the flights I took to that airport, there is always dream first class. Therefore, it not the distance the main reason, it's also the market of that country. Also to Montevideo, it's always a Max 9, therefore dream business class.

is there anywhere to check if the equipment has been changed to calculate the odds? I use flightaware but don't have an account and it only goes back 1 week. I only flew them once IAD-PTY-GIG and lo and behold the IAD-PTY was changed to a 738 and I was greatly disappointed when I walked onto the plane. The PTY-GIG had a last minute equipment change - we were at the gate about to board and were told to go to another gate (which was pretty far actually) but it was still a MAX so the lie flat seats remained, but because it was last minute it wasn't catered properly and there were no blankets or pillows which made for an uncomfortable sleep. So my experience of 2 has been dismal but they are so much cheaper, pretty much half of UA and AC that I am tempted to take my chances again.

Answering my own question... Better to plan for an old 738 when booking a Dreams seat. Twice, in one case for PTY-ASU and another PTY-IAD, the airplane was not only downgraded to a 738, but to a really old 738 with no chargers, IFE, etc.

PTY-LAX/SFO and PTY-ATL are consistently MAX with lie-flats. PTY-ASU is typically 737-800s, though I've had a 7M9 once on that route. They are now starting to run 7M8s as well, which have American Airlines style seats up front, which are actually worse than the newer 737-800s.

Summary is unless LAX/SFO, I wouldn't count on it.

My PTY-SXM flight went from a 737-700 to a 737-800Max

I used them once CNF-PTY-IAD and return and had the dream seats. This was about 9 or 10 months ago when the miles needed one way was only 85,000 for the dream seats. No problems with the flights. Noticing from your handle. I presume you frequent IAD quite often. I used to fly UA internationally in Polaris into IAD, but it became too expensive since I retired, normally more than double fares to terminate there instead of if I flew into Richmond and drove about 2 hours. Just a suggestion to consider, depending on your base and who is footing the bill, as there are several other nearby airports to IAD where fares are much less.

I am scheduled to fly BWI-PTY and noticed my flight/seats have been downgraded from 737-9MAX lie flat seat to 737-800 max recliner. Anything I can do about that? I know Copa customer service is awful, any success dealing with them on similar cases?

You did not indicate when you are traveling. However, I looked at Flightradar24 and it shows just one flight per day between BWI and PTY. All the recent past flights and upcoming flights show some type of 738 but no Max9,

*Clarification: when I originally booked the flight back in July this flight was 737-9max(lie flat, reason I booked it) I am travelling next week noticed it has been changed to 737-800. Any chance for compensation or free change to IAD-PTY?

You would need to contact Copa to see about any costs or compensation. I doubt there would be compensation, as I believe they indicate on their site that the aircraft type can be changed. Switching to IAD provides 3 flight options. However, the two early flights in the day also have the 738 scheduled. The last flight of the day, CM444, has the Max9 scheduled and for the past week no aircraft type change is shown in Flightradar24.

You will be given the thanks for preferring Copa. Equipment is not guaranteed.

These days I'm flying Copa to get to my destination and Delta/LATAM with an extra stop in S�o Paulo on the way back, with guaranteed lie flat or suites, and of course, great food.