Maybe I can help. I have had the original MPW since it was introduced. Unless you have the newer Pro model, we have the same 2TB device. Over time, I have come up with some Best Practices for using the device.
One practice being is to always connect it to my home wireless signal from the router. It works a lot better this way versus connecting iPad to the MPW own wi-fi signal. The only time I use it this second way is when I travel with it. This way the MPW must be real close to you and your iPad for maximum signal strength between the two devices.
When the MPW is connected to your router, the MPW must be very close (in same room) to the ROUTER for best connection between MPW and router. Even if the router is upstairs and you want to be downstairs on the couch to view media from it on your iPad, this is true. In this case, you need to be sitting anywhere in the house where your router signal is a good strong one. (So, advantage #1, you can sit almost anywhere with a Pad or Phone while MPW is close by router and connected to its wi-fi). To be clear, under this condition you must connect to the router wi-fi and NOT the MPW wi-fi. In all cases below I am using the My Cloud app to connect my mobile devices to access home network and MPW content.
Advantage #2: Although the MPW must connect to the router 2.4G wi-fi, If you have a dual band router YOU can connect mobile to the 5G signal of router for faster and better connection. This is how I always connect iPhones and iPads to router anyway, and since both bands are on the same network, my devices always connect at their best speeds because I stream a lot of video to them.using My Cloud and other apps. If you are not sure your MPW is connecting to the router each time you turn it on, then check the Dashboard app, or do the reset procedure again, get onto the MPW signal to begin with and use the My Cloud app to get connected to the router, and when connected this way, change your mobile device over to your home wi-fi and forget about ever connecting to the MPW internal wi-fi again unless away from home or need to reset it again for some reason.
I do not keep any of my personal photos on the MPW, but I do keep my entire iTunes music collection and movie video collection of HD movies on it in mp4/m4v format. They stream perfectly to iPads, and these files are a lot more complex than jpg photos, although photos (and videos) from newer iPhones can be a challenge. I still have the sample media files that came on the MPW drive and the photos, music and videos work fine. The sample videos in this folder are a little bit of a challenge sometimes since they are high bitrate, but second time through them is perfect. I keep them on the drive as a way to test if I need to.
Also,I have the My Cloud cache Setting of app set for 20 GB on my 64 GB iPad 3. Check yours and turn it up; just don’t go to full capacity of iPad.
OK, take all this into consideration as you set up and peak out your MPW system, and let me know how things go for you. One thing is for certain, you need a good modern dual band router, but if you don’t you likely need a better one. Good luck.
Unfortunatelly, photos were still opening with lag. As for video and audio - in my case they work fine as well. The lag occurs only during the opening of the media file. When the file is open (video or audio) it’s streaming quite good. But when I want to scroll throught 50 000+ photos it lags pretty much on each photo.