What's the trade off (if any) for using a credit memo as opposed to adjusting Invoice/Sales Order quantities? I find that I'm getting inaccurate results when pulling saved searches when there are credit memos out there. Should I just include them in my transaction types and be done with it?

I would say for traceability purposes - if you sold 10 but they only took 8 and you credit 2 then you can track that vs just making the invoice 8

Agreed - depends on how you look at it. One way of looking at it is that your Sales Order should always represent the amount the customer ordered. That was always 10. If a Credit Memo is removing 2, that's saying that for whatever reason the customer didn't want 2 after the fact (after they paid or were billed) - this also would be traceable via an RMA process if you have one. Adjusting the sales order is like saying "the customer called after they ordered and decided they only wanted 8". If they hadn't paid yet (or all 10 hadn't shipped), I'd probably just change the 10 to 8. If not, I'd use a Credit Memo and make sure there's a solid RMA process w/ reporting in place. Either way your reports should look for credit memos if they need to.

Thanks @Nicolas Bean and @al3xicon! Makes sense.

Also there's the period issue.. Can't edit amounts in a closed period

indeed

@KevinJ of Kansas True, good call.