gjlamb:
5.5 or 8 hours seems extreme for only 1 photo uploading in that time. What I have observed is that the photos go up in batches. You should not see the count decreasing by only 1 at a time (unless perhaps for a video). I see it decreasing by 20 or maybe 40 at a time. The count sits for some time until that batch gets uploaded, then gets decremented by the size of the next batch. The size isn't alway exactly 20 in my case, either, but some number around that, and it seems to vary. You and I have the same upload speed, but perhaps you have many more multimegapixel photos than I do. You SHOULD see progress over time, however slow it might be.
As I've said several times already, there are a couple of ways to make sure of progress. You obviously monitor the Preferences pane for Photos for the number of pix remaining to be uploaded. You can also monitor the Network pane of the Activity Monitor. Finally, you can log into iCloud on a browser to see what pix are there. If you scroll to the end of the available pix, you should see a count of the pix already there. That number plus the number remaining should equal roughly the total number of pix you have, minus whatever pix are in transit. One caveat: I suspect that each frame of a video counts as one photo in the count reported in the preference pane, because my count started at over 10,000 photos, while Photos itself says I have 8000+ photos and videos.
If I'm right about that last conjecture, then you might appear to be stuck when a very large video clip is being uploaded. Just a thought, anyway.