I have a DriveSmart 61 and generally like it. The screen is especially nice, with almost no bezel. Garmin made some changes to their automotive devices around 10 years ago, and ever since then, they have had a series of odd ways to display your saved locations (aka waypoints or favorites). This model, and others from the past 3 or 4 years, displays them as ugly big "hearts" with no labels, regardless of whether you use Basecamp to pick a symbol. And there is no way to supress the display of these ugly symbols. There are menu items that should allow you to disable them, but they don't work. Now you can edit the waypoints on the DriveSmart itself and choose other (equally ugly) icons, but that is tedious. Anyway, this is one thing that some people dislike.
Also - just checking - I assume you only want to use this device in your car? It would not be appropriate at all for handheld use on foot. Due to the very narrow bezel on the screen, I find it almost impossible to carry it without accidentally activating things on the screen. And, of course, run time is very short on battery power due to the bright 7" screen.
Many of the features of the device, including traffic, also depend on a bluetooth connection to your smartphone. This isn't really a bad thing, but may not be immediately obvious when considering purchasing this device.
There is about 15gb of internal memory, which is plenty of room to spare. You should be able to load quite a few maps without adding a microSD card.
While topo maps will work on this device, their display is not optimal. This is nothing new, all of Garmin's automotive devices have had similar issues for over 10 years (the old models were actually a bit better with topo maps IMO). The biggest issue is that many POI's just don't appear on the screen. And personally I dislike the overally style of map rendering, with very thick elevation contours cluttering the screen. I make maps specifically tweaked for Garmin automotive devices, such as
https://boydsmaps.com/boyds-map-of-new-jersey-2018/ I am not aware of anyone else that gives this much attention to how topo maps look on automotive devices however. And here is a special map that I made specifically for the DriveSmart 61. It's a good demonstration of how the processor in this device is faster than the older models - this map won't work properly on them.
https://boydsmaps.com/lidar-in-the-pines-sd/So those are my thoughts. Nice hardware - especially the screen - and at a price point that is lower than older premium Garmin devices. You can get especially good deals on factory refurb models if you shop around (factory refurbs are "like new", with full one year warranty). Just don't expect it to be an 'outdoor" type GPS device. It's an automotive unit that was primarily designed for use with the City Navigator map, and it is not optimum for working with most 3rd party topo maps.
BTW - the DriveSmart 61 has an interesting "cousin", the DriveTrack 71
https://buy.garmin.com/en-US/US/p/601687While they market this for use with their dog tracking systems, AFAIK you can just turn that feature off. And you get basically the same unit as a DriveSmart 61 but it includes a pre-loaded 100k Topo for the whole US plus compatibility with Birdseye aerial imagery and a one-year free subscription.
https://buy.garmin.com/en-US/US/p/70144This is rather remarkable, Garmin has never offered a large screen automotive device that is compatible with Birdseye before. While this device is more expensive, the included topo map and birdseye subscription would cost about $130 if purchased separately. And Birdseye is not even compatible with the DriveSmart 61 or any other automotive devices.
I have never actually seen one of these devices in person, but find it very interesting.