[iNik]

My experience is about the same, but views with large numbers of items (my weekly review/master planning perspective, for example) get pretty pokey, especially for searching.

Sales Management (which is really what you're talking about; CRM is more of a customer service and marketing strategy) requires persistent history on customers, contracts, call logs, notes, etc. You probably COULD shoehorn that into OmniFocus, but a great deal of those things are not tasks in any sense of the word. There are other programs that are specifically geared to this kind of work and therefore do a better job of it.

Entourage is an obvious choice for CRM that's nicely integrated into task management as well. There's a lot of other Mac-native tools, too.

Take a look at Redlein Account Executive; Now Contact, Now Up-to-Date (soon to be NightHawk); Contactizer Pro; and Bento from Filemaker (a bit of a roll-your-own, but you might like that).

Then there's hosted solutions like Zoho CRM and Highrise, and open-source web solutions like vTiger and SugarCRM -- both of which you could even set up locally on your Mac, if you wanted. And, of course, there's Salesforce.com, but that's very spendy. Probably overkill.

There's no shortage of good options out there. It seems like you're just making you life harder by trying to put it all into OmniFocus.