I can not and will not make a judgement call on your playing and or on how you and your piano meld together. I can say that yes, pianos, one from the next can be very different. I don't have to tell you that though, you already have personal experience with your teachers piano and your own.
One other thing, one session to the next can be different as well. I remember being with my teacher many years ago and doing marvelous things and getting home where it fell apart. Some of that is the energy of the moment sort to speak. I can play a new piece wonderfully if my wife is in the room to hear it and the next with her not there it's just so so. If my sister in law is around just forget workng on a new piece of music, her presence just plain derails me.
My own grand piano has light action, I weighted the keys to have more resistance. My old upright I had many years ago now was a bit sluggish. It wasn't that the keys were so much heavy as just slower responding compared with a grand ( most grands I've played, which some were heavy and some light action).. My teacher had a Steinway, the keys had resistance but accurate, trills went wonderfully and got home turned to mush. Had to have a grand, I just did and so ended up with one.
Also you should know that it is possible to weight keys for less resistance ( would take a tech willing to do this for you and of course costs money). Reweighting doesn't always mean more accuracy. Grands have a purpose besides their style. Choose carefully if you go down that road to be sure you get what you want.. My personal grand piano is a 30 year work in progress ( I do most of my own work on my piano) ! My personal feeling is grand pianos are worth investing in. NOt everyone can, even I did bartering and a bunch of extra work to get mine which was a partial rebuilt one.
To me digitals are good " also have" kind of pianos. Or if a person gigs a lot. To me they don't substitute for an acoustic, though many people would argue that point and so be it.. Also their silent mode is a great thing to have, play with head phones you're the only one listening, wonderful. I prefer a stage piano as a digital, Kawai MP 6, Yamaha C33 type pianos are professional grade, hook to sound systems etc.... At that level they begin to be worth including but not substituting for an acoustic.
All my own personal view or experience,
David