Thanks for the comments. I ordered mine from Summit Hut, I think. They are Sierra Designs brand, black/grey in color, and they have a loop and hook on the inside part to attach to a tent pole. I've been thinking the hooks would make a nice attachment for a gear loft or clothesline under the tarp since I hang this tarp under the ridgeline.
I've heard about the need for balloons, but I'm not sure you need them on the panel pulls, as the force is perpendicular to the fabric. I can definitely see how they'd be needed if you used them for side tie-outs parallel to the fabric. OTOH, I just got this tarp and the grip-clips, so don't have much field experience beyond the backyard yet, though they held in moderate wind the other day.
I haven't left mine on the tarp. I think they would probably stay where I put them, but I'd rather take them off and replace as needed. I placed a small "x" where I like them best so I can be consistent (and know where to sew the tabs). They do stretch the fabric and leave some puckered area behind, but it's not too bad. Not sure how much wear there would be after some use, though.
That, by the way, is my main concern about these and why I think I'd like to add sewn-on pulls. I'm not sure how much abrasion that sil-nyl will take from these. Balloons might help that, though. I figure I can always take a couple along to place in different locations as needed, but honestly I can't right now think of a situation where I'd need them located anywhere else. There are so many tie-outs on this tarp that I'm not sure I'll ever use them all (though I did add four on the 11-foot sides to be able to close the doors).
The other issue making me want to sew some permanent tabs is the very real chance of losing all or part of one of the clips. They are very subdued in color and I almost lost half of one in my backyard the other day. Also, it is more "fiddling" time to set up, and I don't like to fiddle in the rain.
Otherwise, I can totally see just using these all the time and never sewing the tabs. That's why I'm not in a great hurry to get it done.