Introduction and Disclaimer

Like quite a bunch of people I've been using Astroart 4 for different purposes of Astro Image processing. I've never used it for image acquisition or guiding, and I do not intend to. Therefore this review will cover only typical astronmical image processing processes I use.
Furthermore the opinions expressed herein are my own and therefore biased. I'm not in any way related to the Astroart producers or to any other company in the field of astro imaging. I also do not take over any warranties. This is information only from my personal viewpoint. This is definitely not intended to be  marketing or advertising for Astroart. That said, let's start.

Getting it

Getting my copy of Astroart5 was straight forward and easy by going to the companies website. In the download area you will find a restricted demo. which I really recommend to make sure, that this is the right software for you. Personally I did not care, as I was very happy with version 4 and therefore went straight to the orders section of the website. After registering my version 4 I was able to purchase the upgrade for a, to my mind, very reasonable price. The website states, that it might take up to 12 hours to get your download link. Fine with me I thought, but was very happy to get that link within 30 minutes. You will get not only the program and its manual, but also some sample picture to try out several functions.

Installation

The installation procedure went smoothly on my system (a one year old laptop with 4 gigs of RAM and a modest graphics adapter, running WIN7 HP 64 bit). 5 mintutes later I had the system up and running. One mysterious effect during the installation puzzled me: I could not copy and paste the activation code from the mail into the program. Well I could and I did, but then the code was not accepted. Typing it in, it worked. Don't ask me, maybe formatting. Well, there it was and it started right away.

First steps

If you want to see the list of new functions, follow this link to the Astroart homepage. This should give you an idea of what has been going on. The first steps I took were done with some old material. I could give you comparisons between images done with AA4 and then with AA5 based on the same data. But given the fact, that I also learned quite a bit on image processing over time, I am not comfortable with that.

Preprocessing

The first preprocessing was tested with a dataset consisting of 15 luminance frames , 8 darks, 8 flats and 6 bias frames of my Moravian G2-8300. Turns out, that the alignment works fast and reliable. Since you the preview is fast so, checking every picture makes sense and is not too cumbersome. Configuration of the process is easy and straightforward for the deepsky pictures I used. One drawback: while you can use standard multi-select actions to drag and drop the files to the different frame categories, no multiselect is availble in these silos. Example. When stacking the color frames I exchange all lum and flat frames, but the dark frames remain the same. I was not able to mark all color frames and remove them in one go, but had to hit the delete button several time to remove the red frames and get the green frames into the preprocessing dialog. But that is a minor quirk.
The results of the stacking are convincing. Not convincing  is the 200% drizzle function, which resulted in a chequered pattern in the final image. However, the manual also gives you a hand in correcting the artefacts caused by the drizzle algorithm. The pattern seems to come from the algorithm used, which (according to the manual) requires the pictures to be undersampled and a higher number of  images I typically take. DSS returns better results in that area with the same dataset. I leave it to people with different equipment to check the function out, as my material is not suitable for the test.
Nevertheless: preprocessing turned out to be faster and more accurate than in version 4. Like it.

Filtering

First of all. The new cosmetic filters are good and fast. The remove line produces very good results when removing satelite trails. The compress stars functionality is a good alternative to deconvolution to reduce the star diameter and, if activated, can also correct some elongation due to small guiding errors. I would not use it excessively though, as it can lead to some rather not that nice artefacts. The remove stars filter definitely removes selected stars, don't ask me what to do with it if we actually want to image stars (ok, the manual states, that it is useful for comet photometry). Deblooming filters are also for the one of us, who have non-ABG cameras.
A new addition are the remove gradient filters. They are very helpful and deliver very good results. The only thing I miss is a masking option, like in fitsworks, but up to now, the results show that it was not neccessary.
All filters are very fast (a lot faster than in v4) and you have a preview available while still adjusting your parameters, which is very helpful.

Color functions

The color functions look familiar. New is the color curves functionality, which enables you to adjust the color tones interactively. In this dialog you can also add additional control points, as it is also availble in the Histogram dialog. This gives you addtional control on the transfer function. The saturation dialog added a feature to ignore the backgroud up to a given level, thus enabling you to enhance the color of a picture without enhancing the color noise. The only issue I have is, that I ran into a reproducible bug within the saturation dialog. It causes an exception, which is caught, and you can continue your work, so no harm done (I think). but it is sort of annoying. I reported the bug and it is currently under review.
The trichromy dialog is a lot faster and makes it easier/less tedious creating the color pictures and balancing them.

Aligning and other stuff

The alignment using all-star algorithm  works a lot better now and also supports rotation of the frames.And there is an "Align all" function, which is very handy (hated it to do that myself, image by image). The functionality works fast and accurate.
What else did I try? Histogram stretch (nice, but not sure if I really need it) and plate solving (fast, good, nice)

Conclusion

There are still many functions I did not try and quite a lot I personally do not use. So, there is nothing better than having a look of its own with the demo. But what I can say after the first 5 days is, that I have seen a lot of improvement and I like the version. I used it on some old material, so have a look on the images below.