Depending on your environment (assuming you're using C7000 enclosures?) you might be able to get away with using the SPP in tandem with Enclosure Firmware Management; that'll allow you to do the firmware relatively easily if you can afford the boxes being offline. It's a slow process though, and riddled with gotchas - for instance, it'll fail if your update ISO is bigger than 4GB so you need to make a custom SPP which... well, goes against half the point of the SPP really.
For our windows boxes we normally do drivers and firmware in one fell swoop during the maintence window; run up HPSUM on a workstation, point at your windows servers, it'll go do its scan and be able to apply firmware packages as well as updated drivers and software. Sometimes this is a bit hit-and-miss (e.g. a NIC firmware or driver update would take the machine off the network so HPSUM couldn't continue doing its thing) but we've not had a problem like that for a couple of years now. Then reboot the box to apply the new firmware. It's technically riskier than doing the two separately yes but makes for vastly lower maintenance overhead.
Your HP rep might tell you that OneView is The Way Forward and will make your firmware management issues go away. Short answer: no it won't. Long answer: f**k no it won't and you'll lose sleep, hair and SLAs over it. Avoid at all costs if at all possible.
It's really only our ESX servers we care about here in terms of firmware (windows and linux nodes get fix-on-fail treatment unless there's a security vuln) so we can take them in and out of service relatively easily and HPSUM does an OK job of updating the firmware and agents on them without issue. Now if only HP would learn to start doing QA on their firmware releases we might start seeing some customer satisfaction.
Long story short, our experience is that keeping up with HPs furious release schedule for fixing all their own bugs is a rod for your own back and you're better off holding off upgrades that aren't applicable to you and are only feature enhancements (or can be mitigated through DiD). Quicker to read the release notes and decide upgrades aren't worth it than to do HPs QA for them IMNSHO
I too used to have upgrade-itis but five years of dealing with HP firmware has made me exceedingly conservative in this regard.
/cynical and occasionally exasperated HP customer that found this site after investigating the word on the street for commodity whitebox builds