I'd like to understand more about how having multiple collections makes it easier (in what ways is it easier?). Having a separate collection for traders seems redundant when there is a for sale/trade category within the collections.
I used a separate collection for building my 1978 set (and trading dupes from it), and have come to the tentative conclusion that it didn't make a difference. But I should note, I don't (yet) use the site to keep my PC catalogued. I only use it to facilitate trades with a trade list and want list.
I have contemplated having a separate collection for my bulk low-grade traders (instead of editing the condition of them all individually), but I only see that being useful in the scenario where someone would be browsing and enter that specific collection intentionally (since they'd come up on trade matches un-flagged just like my regular traders). I'd have to sort through a prosal to see where each lived to know from the catalog if it was low-grade or not (right?). For example, I have 600 low-grade 85 Topps football cards from when I was little. I also have about 50 high-grade 85s for trade. Regardless of what collection they are in, cards from each will show up on trade matches. Keeping them in different collections might make it a fraction easier for me to track down which are low-grade and which aren't (vs pulling the cards and seeing), but unless the potential to trade partner knows to look and does that work himself, having the low-grade cards aren't going to make a difference to them. (Right?)
When I look at people's collections, I always choose "all collections" and search their trade list there. I don't know what their different collections mean to me, I just know that if they are in a trade list, they are available.
I'm always looking for an easier way.
Generally, the condition I look for is: 1800s-1929 - G and up (1+)... 1930-1951 - VGEX and up (2.5+).. 1952-1967 - EX and up (5+)... 1968-1978 - EXMT and up (6.5+)... 1979-1994 - EXMT/NM and up (7.5+)... 1995-present - NM+ and up (8.5+)