Very different set of customers. Rackspace's self-service cloud has always kind of sucked, and they knew it -- they'd much rather work upmarket with companies that want to outsource infrastructure engineering as part of their hosting bill.
Shockingly bad pre-sales though - in my last job I tried to engage with them on the hosting for a large scale ERP project for a multinational and they were pretty reluctant to get involved even though they advertised that they were targeting that niche and claimed expertise in the ERP application.
This is really a huge difference in the enterprise space. Projects are won and lost on the most trivial things, and having very intelligent people in presales is so critical.
Did you run any benchmarks? Because I was looking at both during the same timeframe and Rackspace offered about 20-30% more 'operations'/dollar in our case.
Looking at their site it seems now what they do is resell AWS/Azure/Google offers, which is weird (and dedicated servers, which was what they always did)