@Highlander -sorry been busy.
Most times if you're using a hardware (or 'clever' software) load balancer, you're going to terminate SSL on that device. While some lower end devices might use OpenSSL, the bigger payers will have something like a Cavium Nitrox SSL processing chip, which won't be vulnerable to this attack (but might be to others, of course). Better software load balancers might have a different proprietary stack also.
Often,the range of ciphers supported by hardware is smaller than OpenSSl so it's possible if the device is configured away from the default that it might fall back to OpenSSL, which could be a vulnerable version.
However, I'd say that in general sites which are using high end Application Delivery Controllers (posh load balancers) are less likely to be vulnerable to this and other TLS based attacks.