Whilst we can debate who's the lowest of the low when it comes to lo-co airlines, and I suspect there are actually worse than FR worldwide, sometimes it comes down to your own personal circumstances as to whether or not flying them works for you.
So yes, you'll be charged for a preferred seat. You'll be charged to board first (although often this is bundled with seat selection). You're not guaranteed to have your overhead carry-on next to you because once the bag limit is reached, it'll be taken from you and put in the hold, so you have to wait to collect it. If you have checked baggage anyway, you'll have to pay for it. You quite likely won't get a airbridge, but will be on a bus to a remote stand.
The upside of these policies, which is where FR diverges from the legacy carriers, is that it's much easier to despatch a plane so turnaround times and on-time performance are much, much better. Baggage delivery will be in line with the rest of the industry, certainly no worse.
Play them at their own game - no checked baggage, the very smallest bag that will go under your seat, take whatever seat you get allocated, don't spend when they start bringing the lottery cards round - and you can end up with an absolute bargain fare. Start adding in the niceties and the bill mounts, often to the extent that a legacy carrier will be as cheap (this particularly applies if you have status).
You just need to work out what you want, what you actually *need*, and make a value judgment.