You really have to consider several factors of the phone. If it's brand new, or high priced, or sought after - you should check eBay prices to see whether selling it there is economically safe. Keep in mind you pay eBay and Paypal once everything is done. You've also got fraud to think about.
The benefits of the recyclers is clear when you use a reputable one, and as long as you don't lie about the condition of the phone then you'll get the money you were quoted. I've just recycled a phone through Sell My Mobile Phone - Sell Your Mobile Phone | OnBay Recycle
and everything went well. It's a comparison site so I got a fair few quotes, to be honest I didn't choose the highest offer simply because the reviews i've seen over time suggest the highest offer can sometimes mean the most hassle.
In the UK there's things like Loot, Craigslist and Preloved too. Still some scammers but not as clingy as ebay.