Best seating for Tokyo Bay Fireworks?

Greetings all,

I'll be in Tokyo on August 10 and I'd like to get a reasonably decent spot to view the Tokyo Bay fireworks. I will already be in Odaiba that day to attend Comic Market, which ends at 5pm. If I go directly from the Big Sight to Harumifutou Park, what are my chances of getting a decent spot?

I might be willing to spend extra money if it means avoiding a hassle. I have heard there is paid seating available. Is this true / Is it worth it? I can't find any information on this...

For any spot in Harumi, you need an entrance ticket (free of charge, by lottery. You need to apply online by July 16), or pay a donation to get an invitation ticket (either 5,000 or 7,000 yen, you need to purchase via Pia ticketing service).

http://www.city.chuo.lg.jp/ivent/toukyouwanndaihanabisaimeinn/

Actually the Ariake area including Tokyo Big Sight is also counted among the "good viewing spots" for those without tickets. By the time you leave the venue, you will find that the area around you is quite packed... I mean, seriously, people line up to secure space from the morning...