As a PTO, I also believe there should be a choice.
My local market likes the constructed format since many of my players come from Yugioh, where constructed is the format of choice. However, we are also aware of large sealed following 600 miles up the road. So the opportunity to provide both allows our communities to mix on a regular basis.
I dont think starting times are the issue, regardless of when you start, if one runs a PCQ by the book including best-of-3 playoffs and untimed finals, it is going to be a long day. I believe the playoff format as well as the current metagame (Control decks in particular) are to blame for drawn out events.
I am aware that an attempt to change the playoffs to the one game format failed due to a backlash from the playing community. I understand that Players want the best chance to win and the 3-game format delivers that. However I hope you consider all the people affected that will not be voting: the Parents who drop off players first thing in the morning and pick them up last thing at night , the Player who drops despite an X-0 record because they have school/church/work the next day (Had 3 last weekend) etc. I'd also to see a return to Finals that are actually played (no prize splits) so I can showcase those games, almost impossible in the 2-a-day format.
The downside is for me is that Split PCQs will increase my overheads (eg venue, transport, staff etc) but for the peace of mind and a faster happier event, it will be well worth it!