Second attempt -- I hate it when a typo closes my tab!

April 30 LGA-MKE
The seatmap for my flight was never accessible ("format exception"), regardless of browser. I arrived at the gate ~35 minutes before departure as zone 1 had just been announced to board. I asked for an upgrade and was told to go to the GA at the other gate - she took quick care of me, and I got the last biz class seat.

May 2 MCI-atl-LGA
Seat maps showed 8-10 seats available on both legs two days before departure. This went down to 4 and 4 the afternoon before departure, and by 10:00 pm the day before departure there were still 4 seats left in biz class on MCI-ATL, but ATL-LGA was sold out. After I cleared security on the morning of the MCI flight the seat map still showed 2 seats available; but at T-45 minutes the GA told me that no seats were available (despite my seatmap showing one empty biz class seat), unless the one person who had not yet checked in missed the flight. That is exactly what happened - I was handed a new BP in the middle of zone 1 boarding.

The storms in the midwest caused my flight to be just late enough that I ran to my connecting gate just in time to see the jetway pull back from my connecting flight. Customer service had already booked me on the next flight - I asked about upgrades and was told that biz class was full. I then asked the type of plane, and when told it was a 717 I asked for either 10A or 10C and got 10C. So many people missed the earlier flight to LGA that my new flight was oversold by 11!

Instead of replying to this post I'll add my experiences from this past weekend here:

May 7 morning flight LGA-MKE: seat map showed all biz class seats available at 24 hours before departure; in the next few hours 3 seats were filled. No changes to that occurred until I got to the gate; at 40 minutes prior to departure I got the 4th seat. A couple more seats were taken prior to the closing of the cabin door, but several were empty for the flight.

May 9 morning flight MKE-LGA: seat map showed all biz class seats available, even at 1.5 hours prior to departure. I got to the gate 45 minutes later, and got the first biz class seat. Shortly thereafter, an Army officer with 5 Navy (Coast Guard?) students boarded; all were given unofficial upgrades to biz class. Two others boarded later with BPs for seats taken by the military; they both chose to sit in the bulkhead seats rather than make the officer or students move. The were 3 empty seats in biz class for the flight.