Here's where it stands ...

... Blab's current Gallery is fine in terms of appearance and integration with the member database. Things could always be better, but for the most part it does what it should. Except for something that has killed my interest and ability to continue with that bit of gallery software: the upgrade and administrative maintenance have become prohibitive. Have been using that software since 2007 or 2008, I think it was, and this has not gotten easier. The upgrade process is not stable and always ends up taking many, many hours over a week or two going back and forth with support trying to fix it. Often it has required some re-coding. It has become a deal-breaker. (And I've confirmed with other users that this is just the way that management does things.)

Bottom line ... Blab must have a different software for the photo gallery for contests/shows. It can be an online service or an install code software, either will work. It needs to be easy to administer and upgrade (if I'm the one do it). Support is readily available and effective. For the users, easy uploading, easy use with readily apparent functions.

It MUST sort by filename. It can sort other ways as well, but if it doesn't sort by filename, it's DOA.

It MUST work for tiered albums - that is, one album as a subset of another album, for the big Blab summer show. We have major divisions, sub-divisions and classes.

It MUST have virtually unlimited for photo capacity. The summer show has photos in the thousands.

I am willing to pay a small monthly fee for good features.

Here's a killer problem that arose with the latest attempt to use Photobucket: especially for the larger photo files, it took forever to display a single photo. That is, click the photo to see it as the full display of one photo, a minute or two later you might see it. I ran into this with some file-sharing apps as well. Prior to PB, used another online gallery for last fall's photo contest, but it they hadn't exactly told me the truth about some of the features, so that ended up being a discard.

SO ... it MUST easily display photos of any size as full-screen at a click, without a wait.

Recommendations? How does work with each of the points above? Please only suggest what will satisfy all the requirements , thanks.