Well that was bloody awful. I'm going to aim for constructive criticism. Feel free to just read the bold parts.
(My time is PST, and the event on FF was scheduled for 7 o'clock.)
#1 - If you give us a time, show up. If you aren't going to show up, tell us. If you can't tell us, when you do show up late, apologize, or at least offer an explanation! Don't act like it didn't happen!
We logged in at quarter of 7 for the Frostfell event. At 5 of 7 we were buffed, had our book with our names, ready to go. Half hour later, nothing. 45 minutes, nothing. A full HOUR later, a serverwide broadcast went out, saying that the Gladiator event would be starting. Huzzah we all cheered, at long last!
But no.
That was immediately followed by another message, saying it would be starting... in another hour!

No explanation, just la la la like it was on time.
#2 - Don't leave people behind!
Finally, two hours late, an LeO asked for leaders to /tell him. A few minutes later one came to me, and I gave him our list of people as requested. He told us we'd be contacted shortly. Twenty minutes later our buffs were getting short and I asked him if we needed to rebuff, or what. He said we'd be given warning to buff. At half past 9, we were told to prepare ourselves and /tell when we were ready. I sent a tell to the LeO, and we were ported out to the hill. We were told to wait where we were, and then they started porting in other people from the opposing team. The other team edged closer and closer, and then bammo, the LeO said go. After the fight, one of our fellow members asked why he had never been teleported. Yep, despite his having been in the fellowship, and on the parchment I handed, he was simply not involved! So not only did we get to wait 2 and a half hours, some of us got to wait that long for absolutely nothing!
Afterwards it wasn't clear whether the gig was up since we'd lost. I had to ask with specificity to find out that was it. So, 3 hours after the event was supposed to start, I'm typing this with nothing to show for it but some screenshots of very bored people jumping around a mansion and about 1 minute of fighting. I don't think I'll be bothering with another gladiator event, and if I do, I'll log in 2 & 1/4 hours late to show up just in time for it start.