Listen, the most important factor in choosing a PPH service is knowing its been around for a long time and is capable of caring for your business. That means, it has a round the clock service that offers real redundancies.
You don't want a company that operates out of a clothing store that can't afford clerks and has a serge protector as a UPS system. You don't want offer your players some dump website that steals ESPN score feeds and looks like it was built by some lego designer hippy.
If you send a $1 or $50 for a service you should get the goods. I want the Bentley operation that gears itself to my business. I don't want to send my money knowing I'm keeping the lights on if you know what i mean.
I want my players to enjoy themselves and that means correct lines, fast grades, good offerings and a stable live service. You want to save money, use coupons or buy shit on sale. Do not use some junk company that offers you the world at a discount.
And for the record, I hope I can say this, stay away from post-up shops that offer per head. I want my business ran by guys that's sole interest is taking care of my business. I don't want to lose my players to that service or have an issue with that business falling into um...problems, in turn shutting me down.
Lastly, there are only a couple excellent per head companies that can meet that demand and one of them has a banner on the RX the others do not. In my personal opinion Per Head is the only provider that gets it right.
Good luck!