We were there this past week, during those very dates. Here are my thoughts on the crowds, based on the parks we hit on those days ...
May 21 -- MK at night. It rained right as we were waiting for the bus to take us there, so I think that cleared out a lot of the crowd. We were able to walk onto many rides in Fantasyland that night. Used FastPass for Pooh, and that worked out well.
May 22 -- MK in the day, MGM at night. MK was nice that day, not too crowded at all. Went to Mickey's Toontown Fair that morning and was able to ride the Barnstormer twice in a row without waiting. When lines were long, we did Fastpass, and that worked out well. MGM at night was more packed, but still didn't need Fastpass for ToT. Only 10-minute wait.
May 23 -- MGM in the morning, Epcot at night. MGM was nice that morning. Went to Playhouse Disney with no wait. Saw lots of characters. No wait at all to see Mickey or JoJo and Goliath. Got Fastpass for Stunts show, and the crowd was massive for that. More crowded in the pm, but not too unbearable. Just use Fastpass. Epcot that night was lovely. Walked right on Spaceship Earth and Mission:Space. Lovely walk throught parts of the World Showcase.
May 24 -- MK in the morning and AK in the afternoon. Another great day at MK. Not crowded at all. Walked onto such rides as Haunted Mansion and Splash Mountain. Used Fastpass for Space Mountain -- highly recommended. Tomorrowland definitely more crowded than other parts of the park. AK in the afternoon was madness. We did the safari, and then tried to leave the park during parade. That was utter chaos. Was not a good first impression of AK for me.
May 25 -- Epcot in the morning and MK at night (for EMH). Another nice day at Epcot. Walked right into Honey, I Shrunk the Audience show. Used Fastpass for Test Track and Soarin'. Finished the walk around the World Showcase for kids to finish their masks and get their stamps for their passports. Lovely walk; not too crowded, but it was hot. MK that night was packed, probably b/c of EMH. We did just two rides and then left.
May 26 -- AK in the morning and Epcot at night. AK in the morning was lovely. We had gotten the safari out of the way earlier in the week, so we went to see It's Tough to be a Bug and walked right in. Then went to Dinoland, which was practically deserted. Rode Triceratop Spin (similar to Dumbo, but without the wait!) three times in a row with no wait. Did Primeval Whirl with no wait. Saw characters at Camp Minnie-Mickey with NO WAIT -- Mickey, Donald, Goofy and Minnie, and some character from Brother Bear. Epcot at night again was nice. Leisurely stroll through World Showcase, and did some more rides in Future World. Spaceship Earth with no wait, and used Fastpass for Test Track. Not crowded at all.
May 27 -- Spent day outside of Disney
May 28 -- MK from noon to 5 pm. Crowds were actually very manageable. I thought they were worse on Wednesday night during EMH than on this day (Saturday of Memorial Day weekend). Lots of locals from FL, but still managed to do lots of stuff. Twenty-minute wait for Small World (but line moved FAST), and 25 minute wait for Indy Speedway. Used Fastpass to manage crowds and wait times. If using standby, wait times for some rides were at least 60 minutes. Crowds were nice, but we had done pretty much everything already and were more relaxed, so probably were not too bothered by them.
HTH! Probably more details than you wanted ... are you sorry you asked??