We have been using Infoblox DDI for 10+ years at Pitney Bowes. The experience has improved gradually. As far as DNS and DHCP go, they are amongst the top ones offering this service. The support is great and downtime is minimal. The IPAM is always scanning the network to update the IP database. The caching servers reduce the lookups towards the internet. All in all, this is a must-have in every data center.
phpIPAM is great for a team environment and complex network environments so all members are informed. It's not very user-friendly for administrators to maintain; a IT individual with Linux OS experience is needed in my opinion.
Reporting is an add-on feature, which requires another system. The basics are free.
Network systems management and reporting is another add-on. However, this is significantly expensive.
The pricing structure is somewhat ridiculous. It's the least expensive system for a duel site. It has 10s of thousands (for a full feature IP tool), but in our case is crazy expensive.
It's generally easy to navigate through all of the menus. It's also very powerful in that there are many options available for configuration, allowing one to take advantage of IP address management tools. This tool is definitely a leader in the space, and provided you have the budget, is a very good investment. The team that uses it will appreciate the tool.
Between Solarwinds IPAM and Infoblox, I'd still choose Infoblox even if Solarwinds is prettier to look at. Infoblox does a fantastic job at managing IP space and really doesn't have much competition in this space. Ease of use, being able to queue changes and having all this done via a web interface that just works is very convenient.