I'm used to asking strictly technical questions, so I hope this "Dear Abby" style is appropriate.
Potentially-Excessive Background
I'm a web designer and developer, good at a lot of things and excellent at very few. I've used various VPS products as development servers, I've tried all kinds of shared hosting, and my high-traffic experience ends with CloudFlare and bumping up resources—no distributed computing, failover setups, load balancing, or big-kid networking. I've set up a mail server and web servers from base distros and know that I'd put everyone at risk offering to do those things for clients. (So I don't.)
Let's say I have a client, a medium-sized company well-established on one of the thriving US coasts, and they run an off-the-shelf PHP/MySQL CMS along with a custom-built PHP/MySQL app. I can keep that software updated, healthy, and neatly deployed—no problem.
Now let's say this client also has an internal IT department that doesn't seem up to the task of maintaining the site and server: inconsistent version control, questionable production "fixes", and with a reluctance to share access, ask for help, or take thoughtful advice.
An otherwise stable VPS has been crippled, and the client knows but isn't sure what to do. I want to help responsibly and not just blame the current situation on iffy internal decisions, but I don't know what to recommend.
The Question
This is a client that benefits from the resources and availability of a good VPS product, with an IT department that may not be well-suited for managing such a server. Does this mean that managed hosting is ultimately an ideal fit?
Management software updates (Plesk, Cpanel, etc.), security patches, and server maintenance should all be handled by somebody other than the client's IT, and ideally there'd be guaranteed, scalable resources with solid uptime and an SLA to match.
I see that Media Temple is offering managed hosting now, but I'm interested in reputable suggestions if this is what I'm looking for in the first place.