Rick, when you say sluggish, exactly what do you mean; from the beginning you have gone from using the ODBC drivers to using the native oledb drivers and from running live queries to running stored procedures.... So, are you saying that you have seen no performance gains at all??? Is sluggish considered .8 seconds compared to .3 seconds in returning a recordset; or are we talking 2, 3,4,5, 25 seconds?
And, how big is your database? How many tables, fields, records? How much ram is in your server?
When I went from ODBC to native OLE DB my performance went from an average return of 3 - 8 seconds to less than 1 second every time depending on the recordset size. I could definitely return 1 record in under .5 seconds every time.
Also, is there a difference in your client machines (i.e. 486, Pentium, PII's or PIII's)
Is there a difference in the network cards they are using? Are they on a different router or hub? What kind of Network?
My personal opinion would be although 98 is a giant 95 bug fix; unless you already are upgrading to 98 or own the licensing; trying 98 probably won't fix your problem and is not worth the money to try.

Last questions, which version of DCOM have you installed? Are you using MDAC2.0 or MDAC2.1? Microsoft just released their abortion fix 3 for Visual Studio and with this a 160 mb Service Pack. Have you tried this yet? ADO is the up and coming technology and is solid in a lot of ways; but, like any other Microsoft product it takes at least 3.0 before it's rock hard. You definitely have my curiosity peaked with this problem; as I am still trying to understand ADO 100% myself.