Pros
Started out with decent hourly rate, but raises were rare and insufficient, so after a few years I ended up being extremely underpaid.
For hourly staff, the benefits on certain long-term temp contracts are health insurance and 401K (with a miniscule match). For "salaried consultants" working with certain clients, the benefits are better and you get to accrue a more humane amount of PTO. My guess is these clients are few and far between, however. They also offer similar so-called perks like webinars that no one ever has time to attend, so, yeah, there's that. And if you do get a holiday or staff appreciation gift, it's a junky piece of swag or a $20 Starbucks card, at best.
Cons
If you're hourly, the PTO situation is criminal. You have to work an entire year to accrue ONE WEEK's worth, and that's all you'll ever get per year - absolutely pathetic. It should be illegal that gig economy rules still apply even when your long-term assignment lasts over a year. Very few of us actually WANT to be long-term temps, but the reality is that as a creative, it's so difficult to get hired in a full time permanent role that sometimes you have to make do with situations like this.