First of all, it comes in at under 250g which means you only need an operators id (as it has a camera) to fly which will cost you £9 per year - although it's worth getting your flyers id too as it doesn't cost any more.
As I own the 700E and 720E I thought that I'd be straight up flying. However, the 175D uses a different app (HS GPS V5), and the start-up routine is significantly different than the top end models (more so the controller buttons and process is not similar). Despite this, the controls are simple to understand and follow, and easily committed to memory. Make sure you follow closely the process to calibrate compass and gyro before each flight.
Max distance stated is 500m which, for a drone of its size and cost, is great. In the UK, drones need to be visible to the naked eye (or with glasses/contact lenses), so it's more than enough distance. I've been out to 250m with no loss of video connection to the app.
The drone is packed with features. GPS enables the drone to return home if you lose signal, the battery gets low, or you decide you can't be bothered to fly it back manually! It'll land within a couple of feet of take-off position. Follow me mode works as advertised - the drone needs to be 5m above ground level for it to engage, and the app is helpful in that it gives warnings before asking you to confirm, reducing the risk of user error when initiating follow me or 360 mode.
It comes with 2 speed modes which I would describe as 'fast' and 'very fast'. The low speed is not the same as 'Tripod Mode' which is a feature on other models. It descends at a decent pace too, so no waiting around for ages until it lands.
Image quality is excellent. Vide quality is good as well, although without any stabilisation, it is less likely to be used for creating content for others.
In comparison to Holy Stone's higher end models, the 175D is firmly in the 'toy' camp, yet has all the same features.
I'd recommend the drone for those on a budget who want a decent product that will give them some great pictures from a birds-eye view.