3.5mm Hyperion , 80 ED, split the Double-Double
You know I like the Hyperion 8-24 zoom. Add to that the 3.5mm, 68-degree Hyperion from Baader Planetarium. 
I tried it briefly last night on the 8-inch LX90 and found it the most comfortable, high-powered eyepiece I have used. What's more, I was able to use it in the morning twilight to split the Double-Double in Lyra with the 80mm Orion ED in my parallelogram mount and comfortable star chair!
Mind you, I have not played with Naglers or other premium eyepieces in this power range just more traditional designs like Plossls and Orthoscopics. But the 3.5mm was (is) on sale at Alpine Astronomical for $99 and is, in my opinion, worth every penny of it. In fact, I am so impressed with this eyepiece that I am going to round out my personal collection ASAP with the 5 mm Hyperion. (Yes, they make many other fixed eyepieces but I like the 2-inch ClearVue 30mm that I have now and I love the 8-24 zoom and that's all I want. )
There are lots of little details about the Hyperion eyepieces that are fascinating, but mean little to my intended use. I suggest you check out this page on the Alpine web site, though, if you think you may be interested. But the bottom line is this: This eyepiece is hefty roughly the same profile as the zoom it appears to be very well made and it gives a very reasonable wide field of sufficient quality to please me. (Caveat. I am not hyper-demanding. I'm quite content with most Plossls. But when you get into these power ranges and especially when I'm using them on the p-mount I want a wide field.
On the 80 ED I was getting about 170X and perhaps a 23-minute field. Whatever the exact size, it was sufficient field so that I could move quickly from the Double-Double to Albireo and other bright targets using nothing but a red dot finder with no problem. But, this is really over-powering the 80 ED up there at about 53X per inch. I take 50X per inch as a very reasonable limit and I seldom use more than 40X per inch. For these reasons I think the 3.5mm will get rare use on this and most of my scopes. I suspect the 5mm will be my hgh-powered eyepiece of choice, except on those rare nights of exceptional seeing.
That said, I could not come near to splitting the Double-Double at 75X, the limit of the zoom. At that power I was getting a strong hint of a rod shape, but couldn't be sure the rods were going in the right direction. The "rod shape" is the beginning step in caiming a "split" of two stars, This an other steps are shown in a chart on Page 6 in "Double Stars for Small Telescopes," the new book by Sissy Haas. (A great reference.) She says the Double_Double can be split to the "touching" or "kissing" stage with a 60mm at 120X. One of the neat things about the Double-Double is one pair splits "vertically" and the other "horizontally." So when I see the "rods" going the right way, I know it's not my imagination.
When I switched to the 3.5 mm they certainly went the right way. I put the stars near the edge of the field. (They were nearly at my zenith at this point.) I had to wait about 7 seconds for the p-mount to settle down after focusing. No surprise there. This mount is designed for use with binoculars and maybe 30X tops. I'm using 170X. But despite the wind, it did settle down and as the stars drifted near the center of the field I had what Sissy calls "split by hair" which is one step beyond " kissing.' (Hey, I like her little chart and vocabulary I dont know if it's original, but it does make it easier to talk about what we mean by "splitting." )
I didnt time it, but I had better than a minute with the pair before I had to readjust the scope and wait another 7 seconds for it to dampen.
When I switched to Albireo the view wasn't great. This was too much power, really. Wish I had the 5mm. I suspect that would have been just right for the conditions. I then trekked over to Jupiter which was low in the south between some tree branches. Uh huh. Way too much power. But I could make out stuff on the planet quite a bit, really. But I could see it just as well and more aesthetically pleasing when I switched to the zoom at 75X.
So what do I like about the 3.5mm Hyperion? Sharpness. Wide field. Good contrast. Comfortable eye relief with no problem finding the right placement for your eye.
Most of this was obvious as soon as I tried it in the LX90, I had a focal reducer in, so the LX90 was functionig at about 360X (it's limit is 400X in my view) and that seemed to work fine last night as I peered through small gaps in the cloud. My first subject was Saturn and I was blown away. I really didn't expect it to be that steady. Funny it reminded me of one of those old, colored postcards. Not the Kodachrome ones, but the painted ones from a century ago. I could see the Cassinni Division clearly, as well as the shadow of the planet on the rings and several moons. I also could see markings on the planet. But I'm not a planetary observer and I only had a few glimpses before the clouds closed in, so I can't really evaluate how good this was. I was able to swing quickly over to Gamma Leonis, however, and found that easily split as it should.
So is my equipment quest about over. I really hope so. My order for the 5mm goes in today and if that matches my other two Hyperion purchases, then I really am all set. I feel the 30mm, 8-24 Zoom, 5 and 3.5 will work well in most of my scopes giving me a great range with very little fuss. I expect to do 95 per cent of my observing with the zoom, reaching for the extreme eyepieces only when the subject and/or the seeing demand it.