i have an orchid, idk if mine is abnormally shy, but it hangs near this little cave zone in the tank almost entirely. i definitely wouldn't call him an open swimmer, which is a bummer because it's a very pretty purple
i've had both and the gramma was cool when it was out and about, then i did a tank switch and it just hid and eventually died. i didn't qt so not really fair to the fish, but i had tried two and both died so i deemed them not very hardy and went the orchid route.
also worth mentioning, i do feel like the orchid is mostly peaceful, it is willing to be a jerk to new fish, especially ones that want to hang out near rocks. it kinda limits you if you want to do more rock oriented type fish in a smallerish tank. mine is a 24x24 cube so if yours is bigger you could do both, just do the gramma first. and from what i've read grammas can go with other basslets (except the closely related blackcap) so that's cool