I was upgraded to Photos beta on my MacBook Pro and at the same time bought a new Mac Mini.
It has not gone well. No matter how often I organise my photos by hand, deleting copies (when some of the older photos were imported from a LaCie Hard Drive the Dates and Times were erratically all over the place..ie my 40th birthday cake dated two years, two days and two months before said birthday); I went through 6 000 photos by hand, re-edited the photos where the editing had been undone, more than once, deleted duplicates (Photo Sweeper did not work) and put in correct Albums; some such Albums are organised not by date but by topic, eg Aberdeen Looks Good In Grey, B&W Portraits; it may have been a mistake to take advantage of the fact a photo can be in several albums (Aberdeen Looks Good in Grey, Old Aberdeen, Kirkyards).
The problems I am having:
I cannot copy my Photos Library to an External Hard Drive (cannot read files);
I cannot share (drag to copy) said Photos Library over the domestic LAN;
If I use/turn on Photostream (or iCloud) it seems to include deleted photos, unedited photos and not organised according to Albums but by the remuddled, wrong date/time stamp (my changing the erroneous ones seems to have been undone); if I delete the whole Photostream on my phone I fear I risk the hard copies disappearing from my MacBook;
My TimeCapsule will not back up successfully (and only tries to back up in part) - and has eaten through one 1TB of storage in < a week with (I have about 40 GB of photos - some however are still missing);
I cannot export Albums only moments (so the Albums organised by theme or topic are all over the place - I spent 80 hours on consolidating this which Photos undid; (my Events in iPhoto were largely thematic not chronological).
I cannot undo this and revert back to iPhotos as the editing is not supported; it is also prone to crashing my machine.
Aperture is gone - no longer supported and I could not put it on this more recent MacBook (I do have elements but it is slow and for certain projects like invitations or prayer cards only).
I wanted to export the reorganised Photos library to the higher HD Memory MacMini to use as a revolving photo frame on Screensave; I wanted then to delete all the historic photos from my MacBook to speed it up (Photos is slower then iPhotos and keeps freezing).
Another problem is that I cannot seem to delete photos except by going into the moments; I cannot then delete unnecesary albums.
I also find I cannot go into Photos Library (without opening it) and view pictures by Album or event.ms i
Finally Photos seems ineffectual at exporting or sharing to Facebook (less so) and Flickr.
I have a Mac because I want an OS and PhotoEditing that works better than a 8 year old Dell did.