I have had both too. No issues when I cancelled (I rotate subscriptions to stretch my "fun" budget) and the designs I have stitched have been fine. I agree with katrinasheffield the two sites have some similar items (and yes, they are mother/daughter)
I have had subscriptions to both sites and have never had any problems with either. Download all you want and if you cancel they are yours to keep. Just don't forget to cancel if you choose because it does renew automatically.
I actually have them both. I haven't stitched too many designs from either - but I have downloaded a bunch. My username and pw is actually the same for both sites (which makes it easy to remember). I totally forgot to not renew my membership - so that's my fault. You cancel it from Paypal - so there shouldn't be any issues. I've cancelled other subscriptions from paypal and didn't have any troubles.
After a while - I've found that I their designs are similar in nature, and you could probably get by with a subscription to just one site… I tend to download more things from a design in stitches than embproject (they are related - mom and daughter I think… it was on their site at one point in time).
One design that sticks out are the small tags - little squares, circles, etc. I also have a similar design from another site that I can't remember at the moment - and the quality was very different - but I could tell that before I downloaded. The one site the blocks were edgestitched and on these sites, they were not.
On the flip side I downloaded the baby stuff - the little zippered pouch, and a bigger zippered pouch and they turned out great. The In the Hoop directions aren't totally easy to find, but once you find em (because its the same for both sites) just bookmark it.
All in all - I would have to say I did get my money's worth, and I've never had an issue with downloading - although it is a bit confusing at first. You click on the image on the main page which takes you to a page with just that design on it. At the bottom of the images there will be a link with the design name on it - this is NOT the drop down box near the bottom - that is for the "per design" people. You could always download one design and pay for it prior to signing up. A design in stitches has a "freebies" link on the sidebar, but it doesn't work. You might be able to email and ask for a free test design since apparently they have them…. (it hasn't worked since they updated their site a few months back).
The hub will be at work on Saturday and I could do a test stitch for you if you'd like also (I'm currently grounded from sewing - except for our bedroom quilt he agreed to - but I have a broken machine that needs test stitching before I can do the quilt :)!!! )