I don't have any problems with the lower CPU count. If you are maxing out 4 or even 2 cores on the new boxes (Xeon E5 v2 chips) for any extended length of time, then you likely are either misconfiguring something or you have a project that isn't really right for the Linode platform anyway. Also, compared to the old boxes, thread for thread the new E5 chips score over 3x as well as the old E5520s (and those were the L versions - lower power) on Passmark:
http://cpubenchmark.net/high_end_cpus.htmlThat said, Linode doesn't (seem to) really care if you max out your CPUs, so if you are CPU-intensive in what you are doing, it shouldn't be a problem.