Update: I met with the guy from Delta Optical last month and he left a few scopes with me to look at. I am sorta going through them one at a time, so it will take a little while.
I started with the Stryker HD 4.5-30x56 that is currently sitting on my Grendel (on the left in this picture):
They have a couple of different reticles available. The one I am looking at is the LRD-1T, which I like a fair bit:
It is somewhat similar to Athlon's APLR in some ways and to Minox MR4 in some ways. SInce I am so used to Gen2 XR, I kinda like the combination of small crosses and dots in the Christmas tree portion. So far, the reticle has proven to be very easy to switch to and I like it more than most competing designs, although this is really personal preference.
I currently have scopes on hand with APLR, EBR-2C, EBR-7, Gen 2 XR, DevL and a few other reticles, so I will be doing a very careful side-by-side with LRD-1T to see how I like it.
My initial impressions on the optical quality are very good. I think this scope is a variant of the LOW design that a bunch of people use in mildly different configurations: 5-30x56, 4.5-29x56, etc. I think these are all related designs and the Stryker seems to be the best one of these I have seen yet. Now, these are really just early impressions, since I have a lot more to test, but the basic optics and mechanics seem quite good. It so happens that I know a few Polish companies in my line of work and Delta is friendly with one of them and uses their test equipment. I think they are able to push LOW a fair bit in terms of QC since they can do a lot of quantitative measurements themselves.
In other words, I am pretty impressed with what I am seeing so far.
Stay tuned for more as I keep messing with this scope and start on the others. I've got them all mounted on different rifles.
ILya