Never been in a 16-Teamer that took 8, but plenty that took 6 (Four Div Winnners, 2 WildCards)...While 8 seems like saturating the playoff field, I've seen many times where a truly deserving Team gets left out with 6...
...so why not 7?
You give the one truly best Team in the League (some combo of overall record and points, or just use the Power Rankings on MFL), a bye, and have the other 6 go head-to-head in Playoff Week 1...you go from 7 to 4 to 2 to 1. Voila...
...just my opinion, but when you have more than 2 Divisions, what's the point in giving more than one Team a bye anyway? Your going to have 3 or 4 Division Winners, and granted, you'll find 2 that are 'better' than the other 2, but that line can sometimes be gray and involve some detailed work to determine. There's almost always ONE Team that's the #1 Seed, and in in my opinion, the priviledge of a bye week should be reserved for one and only one Team. It's a significant priviledge too - one less head-to-head game to play gives a team a much better chance of going all the way. A Seven Team Playoff Field makes that do-able.
...as an aside, I really don't think it matters if a League Championship Game is held in Week 17...presumably, everyone in the League has a complete set of rules made available to them well before Draft Day, a trade deadline through at least Week 10, and most Leagues have a Waiver Wire that runs through the final week of the Fantasy Regular Season. Thoughtful drafting and judicious use of the WW with the rules in mind allows you to plan your roster around a potential Championship run, and avoiding the pitfalls of having Fantasy Studs on your Roster that may be benched by their NFL Teams due to having clinched early...only 12 out of 32 NFL Teams make the playoffs, and I'd venture to guess that on average, less than half of those have clinched berths or byes and can afford to rest players. There are plenty of players who will have statistically valuable performances in those final weeks around which to start building depth around your Studs when it looks like you've got a Championship Caliber Squad in your hands...