Are you seeing very slow auto complete using the Operations Manager snap-in? If so the folks at the Operations Manager team blog may have your solution:
I am a big Powershell fan, and I use the Powershell console regularly. Depending on what I’m taking care of at the time, I might be using the plain vanilla console or I might be using the Operations Manager snapin to work with the latest builds of our product. In both contexts, I find that a tab expansion feature makes my life a lot easier. Powershell V1 had tab expansion support, and with Powershell V2 the tabbing capabilities have been greatly enhanced.
One bad thing I found with V2 tab expansion is that it is SLOOOW to autocomplete cmdlet names when using the Operations Manager snapin. Typing something like “Get-Aler[TAB]” or even a standard cmdlet like “Select-Stri[TAB]” would sometimes hang your console for minutes. This came up on the SCOM newsgroup recently, so it is clearly a problem for a fair number of folks.
To continue reading and to discover the solution see http://blogs.technet.com/momteam/archive/2009/12/09/slow-tab-expansion-in-ops-mgr-powershell-v2-console.aspx
J.C. Hornbeck | System Center Knowledge Engineer