I had a 2014 for 2 1/2 years and we had gas struts. In fact, the 2703WS I've got now has the exact same bed and struts with a Serta on it. The old trailer would stay up, but the new one won't. Same struts, different mattress weight. Pull the one you've got and measure it (I believe closed length and inner rod length) and look online. They're about $10 - $20 ... I had to replace my 2104S door strut last year. I'd look for one about 150% of the one you have now and go from there.
2012 Chevy Tahoe LTZ - HD tow package
2017 Rockwood 2703WS Emerald Edition