I've been using Transcend cards (8GB-16GB Class6 and 32GB Class10) in my HM700 for years and have never had an issue. This past week I did some shoots for a client and used their Sandisk cards. I had nothing but constant invalid media/restore card warnings through out the shoots. Some cards would not restore in camera, but when the client checked them on a computer, they said there was no data loss.

Curious if anyone else has had similar issues, and if its the camera or the cards?
-Thanks!

Bo, like you I use 32 GB. class 10 Transcend cards but have used Lexar and SanDisk cards when I have to.
The Lexar cards are the Platinum II ones and say SDHC 200X class 10 on them.
The SanDisk cards are the UltraPlus ones and are class 10 rated at 48 MB/s.
Never had any issues with either one.

The clients cards were SanDisk 32GB Ultra UHS-I SDHC Memory Card SDSDUN-032G-G46 B&H (http://www.bhphotovideo.com/bnh/controller/home?O=&sku=1077090&gclid=Cj0KEQjwz6KtBRDwgq-LsKjMk9kBEiQAuaxWUuGMkY-cxnW6VIWPtG0IZPgG2d9xR-YP5D8xqaBiMTcaAm_58P8HAQ&is=REG&m=Y&Q=&A=details)

My solution right now is I'm gonna ask to use my own cards, as I feel I won't have any issues.

No reason those cards shouldn't have worked but a big YES to using your own cards because you know that they work.
If the client insists on getting them from you, build the price for replacement cards into your quote.

Did some tests with the client prior to shoot day. We switched the camera from shooting 1440x1080 in SP mode to 1280x720 in SP mode, and had ZERO issues. Could have been the resolution, could have been the cards. Clients happy, thats all that matters.

Clients happy, thats all that matters.

Definitely!!!

I have never had an issue with Sandisk cards but a couple of years ago I did have a catasophy with Transcend cards. 3 new cards in a row crapped out about 7 minutes into the interview--all had the same lot # and a month later I received an Amazon recall.
It spooked me so bad that I talked to a upper level JVC engineer who said all cards can crash on you--in my case an issue with camera buffering exceeding the defective cards capacity to keep up with the data flow. He suggested that (he truly was trying his damnedest to help me in the field) I should take any new cards and as I leave the airport for my shoot; to record on the camera as it sits in the seat pointing out the vehicle--if it has no problem recording the fast moving images past the 10 to 15 min mark, it's not likely to fail. Good advice, a little impractical...stopped using Transcends and been relying on Sandisk ever since.