I've used them twice - first experience was initially good - they got me a good flight at a good price - a little better than I could find on my own. However, after purchasing they kept harassing me with probably a dozen phone calls and even more emails trying to sell me their travel protection package and other upgrades. It was beyond annoying - I had to threaten reporting them to get it to stop. I had kind of forgotten about that - which is why I did try them again.
The second was horrible and I will NEVER use them again. I kind of assumed that their agents are on commission - but did not expect them to straight-up lie to get a sale. Which is going to cost us a fortune now. Long story short we have a baby we are taking on this trip - and when we booked we did not have her passport yet - so we could not book her as an infant in lap without her passport. But I was assured that we could easily add her later once we had her passport. When we finally have her passport - I went to add her and they say sorry the only way we can add her is as a full fare adult ticket. Or we can contact the airline directly. And of course we are flying on multiple airlines so we will have to pay to add her to each leg rather than just to the overall trip. But it gets better - once we try to contact the airline - they say they can't yet because Gurufare has not uploaded our passport info yet - even though I had sent it to them 6 weeks prior...
There are far too many other options - avoid this one at all costs!