The fact is - I have never faced any trouble while using it! It has always supported me all my time, even when some of our projects were quite tricky! Nothing special here :-). Keep supporting your user base as you do not want them going back onto other softwares/vendors once they get used with cacti (as we did for about 2 years before coming over!). Yes its one stop solution provider having metrics tools such DGA's monitoring system alongwith network topology management tool etcetc which saves us lot many times. The best thing about cactus is its ability to deliver quality work with great speed, they never fail to exceed your expectations. They also have very good customer support which is always there whenever you need them. I would say their pricing structure could be more competitive but that's only my opinion. So far I haven't found anything negative so no complaints here! Their team has been able to provide us with high-quality content for our website within short deadlines.