So looks like all my qustions have been answered to wit:

(1) Does this extend to summer? Yes, at least for August.
(2) Is this available on *A? Yes, LH is offering similar fares.

Except for 2:

(3) Will I get a true "lie-flat" seat or do I have to worry about the airplane? (I see one post indicating lie-flat to AMS - but does that apply to all West Coast flight on KLM/AF?) I understood the old AF seats are angled flat = horrible.

(4) Has anyone successfully done open-jaw? Really prefer to avoid returning to PRG for the return (though FCO is okay ;))

Crunched some sample rez on Orbitz for mid-summer from SFO -
SFO-FCO was pricing @$2500 per person with 1 night in a crappy FCO hotel and rather mediocre routing on AC through Canada. Options look better for SFO-PRG which is pricing at $2270 on DL via JFK or on KLM for $20 less via AMS (with a horrendous 12 hour layover)

Per Orbitz "Only 6 tickets left at this price" - LOL better jump on this one!

If anybody is still looking for ex-SFO, I think it applies to most airports in Europe. I found BRU, EDI, and MAN availability in addition to those above.

Have not been able to get more than the 27 days nor open jaw. I am/was looking for both.

I must be dumb or unlucky, but I'm not finding anything remotely close to the prices quoted here. Could someone show me some sample searches from SFO to any of the above? Ideally a week a length. Thanks!

I still see SFO to Munich, Prague, Copenhagen, Catania, etc. in mid August for $1.5K. I'd just plug random cities throughout Europe to see what's out there.

If you're looking for March or April, try LAX -- couldn't find anything out of SFO for the spring unfortunately which was what I was trying to do,

Look on Travelocity. Inventory is drying up on Orbitz and Expedia, but can very well be available on Travelocity for the same dates. You won't earn the OTA cash back but the overall savings are worth it. I'm still seeing dates July - September with prices around $1500-$1800 pp with 1 hotel night.

Try SFO-FLR, 9/17 to 9/24, and choose "I only need hotel for part of my stay" with 9/23 to 9/24. You can book on AF ticket stock in Z fare class for about $1750 pp.

​​​​​​
I finally found something. SFO - PRG 8/18 - 8/26 for ~$1,500. I'm not sure if I want to book it yet, but good to know I'm not crazy! Thanks, guys!

Btw I'm new to DL so have this newbie question. Am I reading this correctly that an AF-operated flight in J will only earn 40% MQD towards DL Medallion status?

These are probably going to be considered "exception fares." The irony is that MQD/MQM/RDM seem to be calculated as a % of distance flown on exception fares, so it may actually work out to reward more miles this way.

https://www.delta.com/content/www/en...html#exception

You will earn 40% MQD assuming you have AF flight numbers, meaning marketed or ticketed by AF - this is the percentage based on the total distance flown. Each airline has it's own earning chart. For example AF marketed/ticketed flight, earn 40% MQD in biz, while DL marketed/ticketed flights will earn based on the amount of ticket less taxes and fees (similar to UA and AA).

DL also has a separate chart for "exception fares" that calculates MQD and MQM differently (eg. travel packages, etc). From what I can tell, no one has flown this fare yet so we don't know if this would earn based on the standard earning chart or if it would be treated as an exception fare.

Ah, I didn't realize it was based on distance. I assumed it meant 40% of $ price.

​​​​​​​
Ah...very helpful. Thanks so much, everyone!

I have an $1860 deal on hold at Delta.com for MIA-BCN around Thanksgiving time. No need to wait for the non-sale price Thanksgiving sales this year!

The package was purchasable for as little as $1711, but the additional $150 gets me 2 nights at the very nice **** Hotel Murmuri in the Eixample, so it's a bargain!

Can't really find any info on the risk-free cancellation policy as to how it relates to Delta Vacations - I assume it would - but there's a 24 hour hold, so I'm taking advantage of that.

Flying MIA-JFK-BCN-AMS-MIA. Sadly both KL and AF fly angle-flats on this route, so I'm sticking with Delta on the EB leg. Don't mind KL's A330 on the return as much though.

Did anybody see deals for ZRH or GVA? Searches for ex-SFO in March resulted in prices in the range of $4k pp.

Saw both later in the year (august and onward)

Well I scored a fantastic deal thanks to this thread, out of PHX no-less! $2050/person on DL/AF to Prague, including 6 nights in a hotel (we aren't throwing the hotel away, we picked a nice one with breakfast and will be utilizing it).

Comes in at 18,599 MQM, $2480 MQD even as an exception fare. I'm going to use it as a status match to DL with my AA Gold status. Wish they'd let me earn DL Gold since I meet the "match" requirements for it, but my status downgraded from AA Plat today. Still excited too, Prague has been on our list for a while.