I've bought the latest available Zen and Crazystone, but I don't think I'm going to upgrade this year. What Leela and zakki offer in terms of playing, and even analysis with some of the free third-party addons and scripts, does not make the commercial engines a worthwhile proposition for me. Especially at the given prices.

I am still waiting for someone to implement a self-play-modus where the engine plays itself from any given position.

also with Leela (GTP engine and editor needed).

It'll likely be v15.3, as this version is currently heavily tested on CGOS. ZenLv9 (also v15.3) ran on KGS with weaker hardware setting to simulate normal end-user computer, 20 minutes main time and 5 periods of 30 seconds byoyomi with handicap limited to 4 stones, achieved a solid 8 dan. Also there will be many level of strength judging from many test accounts on KGS: 8d (strongest), 7d, 6d, 5d, 4d, 3d, 2d, 1d, 1k, 2k, 3k, 5k, and 7k (weakest). It'll support GPU (likely up to one), and 10 cores of CPU (upgrade from 8 cores from previous version), though the GPU gives better performance boost than additional CPU. Actually they test a little bit of v15.4 but it's not better than 15.3.

My guilty thought on this is that I don't want it to release yet until we apply anti-cheating to all go online server (there's already a method but require all developers send all version of their programs to central body)

Zenith Go 7 will not support GPU, according to the mail from ZenAuthor (Yoji Ojima).
Though I am still going to purchase it. Even without GPU, it is stronger and it has better Life & Death judgement than current freewares, so its evalutions are more convincing. I also like its playstyle very much.

Oh why, that's so strange. Can you share a link? If we look at the score of Zen-15.3-10c on CGOS against:
Zen-15.3-1c1g: 31 wins out of 110 games.
Zen-15.3-2c1g: 5 wins out of 38 games.

What are the implications of this? Is CPU only version weaker or what?

ZenAuthor mentioned that:
(1) Zen's main customers are still elderly people in Japan, who do not even know what GPU is.
(2) Zenith Go 7 is about 2 stones stronger than Zenith Go 6, so they think it is enough to be a new product. Perhaps it could be weaker than some freewares with high-end GPUs, but they do not care about that for now.

For the test on CGOS, I guess that they just want to observe the strength with a strong CPU and without a GPU.

I've been observing deepzengo games on WBaduk against Japanese pros, and so far deepzengo has lost only 2 games. Which means Zen is still beatable. Does anyone know how to access the archive of played games?

ZenAuthor mentioned that:
(1) Zen's main customers are still elderly people in Japan, who do not even know what GPU is.