If you want a HEPA filter for a bedroom or for travel (by auto or when you can afford to carry LARGE suitcases, like on a cruise), the Levoit 200S is a great choice.Though another reviewer had the 200S confiscated by a cruise company, we were able to take ours aboard a ship in August 2022. We contacted the cruise line (Holland America Line) ahead of time by email, packed the 200S in its original box with the certification circled in Sharpie to highlight it, and also wrote "FAN, no heat!" on the box with a pen. (We taped the email where HAL told us it would be okay to use on the ship to the box, and also taped a cruise line issued luggage tag to the box for identification.) HAL inspected the unit as part of the checked luggage process, and it appeared in our room without any issue or further communication alongside our other luggage.The 200S in its box will fit in a large (deep) checked suitcase or an oversized tote bag. It isn't too heavy to carry, even for someone with arthritic joints, but it is rather bulky. For home use, anyone of any age or health status should be able to carry this to the desired room and set it up.All users should note that the filter is WRAPPED IN PLASTIC when the unit is brand new. If you don't unwrap the filter inside the plastic casing, your 200S will be totally unable to filter any allergens. Double check this upon receipt, though a sticker on the unit did remind me to take this step when I first unboxed my 200S HEPA machines.For a cruise stateroom, one of the top features of the 200S model in particular is the built in nightlight. My kids were in an inside cabin with no natural light, and the small nightlight was helpful at night. One of my teens will take this to college for use in a dorm, and the feature may also be good there. I tried a Levoit Mini, which is a nicer size for travel, but it is too small for most bedrooms and the lack of nightlight made me prefer to pack the larger 200S for our cruise. (I've added a photo showing the Levoit 200S stacked below the Levoit Mini along with a tiny PURE HEPA for size comparison for those seeking a travel HEPA option.)Best of all, the nightlight on the 200S is only a feature, and it can be shut off with a tap. The operating lights (glowing touchscreen "buttons") CAN ALSO BE TURNED OFF COMPLETELY, so this unit will run absolutely dark. If light bothers you when you sleep, as it does me, this is perfect. Switching the button lights off does make is somewhat harder to find the correct spot to tap to adjust the speed or turn the lights back on, but I only do this once per day typically, so it is well worth the tradeoff.The Levoit 200S will run totally dark, but there will always be a whirring fan noise because air movement is necessary for the filtration to occur. My kids dislike white noise and run the machine on low when they sleep. I find white noise soothing, and usually keep the unit in my bedroom on setting 2 of 3. If allergens seem bad, or during the day on the cruise ship when the cleaners would enter the room, we run the noisier setting 3 for maximum filtration.It's hard to quantify how well these remove allergens compared to other units, but I've seen good reviews of a related model in Wirecutter so I'm optimistic. Certainly, these are lighter in weight and more aesthetically pleasing than the Honeywell models I used back in the 1980's, though the old metal shells felt sturdier than today's plastic ones.No HEPA filter can work properly if it is undersized to the room, but combining two (or more) small machines in a larger room is an option. Having the internal fan pull in air at multiple points can actually work better than one stronger fan operating to one side of a large or irregularly shaped room. Since my bedroom is larger than the kids', we run two units to reduce allergens there, one one either side of our king sized bed.This isn't the model to buy if you want it to work alone in a large room, but it is reasonable for most small to moderately sized bedrooms. The larger the room, the higher the fan setting you'll need for it to be effective. Only air that passes through the filter has allergens removed from it.I've never bothered with the Smart features on this model. Since I'm trying to reduce allergens where I sleep, I can easily reach the controls. I use the nightlight as I get ready for bed and to walk from the bathroom without bright lights on, then I switch that off and climb into bed in full darkness. For me, this model is perfect.