I'm happy with my Sherpa. It provides a solid, tailorable platform to build on.
Attachments:
1. OVS 180 awning on the driver side. Mounted using three OVS plates, each with six carriage bolts on two adjacent crossbars (so three plates, six crossbars, and 18 bolts in all). Sherpa now makes HD brackets and I may switch over to a few of those.
2. OVS privacy shelter on the passenger side.
3. A stack of recovery boards, mounted to two crossbars right above the sunroof.
4. Two Zargas boxes, each mounted with a Zargas mounting plate on each corner, each corner secured with three carriage bolts.
5. Three crossbars have a pair of Sherpa Smiley tie-downs, allowing me to secure a Gazelle T4 along the center of the rack (between the boxes and behind the boards), strapped down with three Rollercam straps.
Additions: Extra crossbars - I think four more than stock. Smileys. Maxtrax mounts. A lot of 316 stainless bolts and washers.
Experiences (with a 2020 version of the Crestone)
(1) Be very careful not to over-tighten the mounting brackets to the roof - stop as soon as the domed bonded washers start to flatten.
(2) The primary lengthwise plate on the passenger side twisted under off-road stress when my awning was on that side and wasn't as securely fastened as it is now on the drivers side. I compensated by moving the awning to the drivers side, and on both sides I now use oversized washers at the end of each crossmember to reduce the likelihood of the bolts pulling through the open channels. Sherpa has redesigned better plates with shorter slots, but I have not upgraded.
(3) One of the front mounting brackets broke after a couple years of use. Sherpa had redesigned a better brace, and they sent one to me free.
Overall impressions:
(1) Well engineered solution for mounting to the roof. No water infiltration.
(2) Many possible points of failure with bolts and connections all over the place. Check everything before every major trip and after every few days offroad.
(3) Very customizable.
(4) Lighter than the Gobi. No rust. Wider overall roof surface. Possibly not as solid.
(5) First-rate customer support. They answer the phone, respond to e-mails, ship things quickly, improve their designs based on feedback and experience, and they back their product.