Paysystems here (and because I like beating dead horses, www.paysystems.com
Been with them about 6 months. They're okay I suppose, as long as you don't need support. If you ever need them, don't expect a reply unless you contact them at least 4 or 5 times regarding an issue. Also, don't expect their anti-fraud checks to do you any good; always manually review the transactions!
If I could justify the monthly fees for switching to a full merchant account, I would go for it. Just not making enough money yet.