FLO recommended these eyepieces to me, after discussing my requirements. And very helpful they were too.
I bought the 8mm and 21mm to go with a refractor 500mm focal length telescope with a two inch eyepiece 90degree mirror eyepiece holder.
I was not disappointed.
These eyepieces are excellent. Easy on the eye for prolonged viewing, with a massive apparent field of view.
I attached my Nikon DSLR to the eyepiece and got some great images. This was my first foray into astrophotography.
The only problem is that the telescope I have at the present time does not allow the eyepieces to perform to their full potential. So an upgrade is next on the list.

I have the hyperions in 24, 17, 13 and 8mm focal lengths and, in short I find them excellent. I use the 24mm for about 90% of my observing and use all of the ep in both 1.25" and 2" configurations across a range of telescopes. Given FLO prices (December 2015) it is very tempting to fill in the missing gaps (21 and 5mm).
Recommended without hesitation.

This is my impression of the Hyperion used with my Lunt LS35THa with B400 blocking filter.

First off I must say this is a large eyepiece compared to my Meade 4000 40mm and 26mm I have been using for Ha viewing. But don't let that put you off,
The build quality is amazing, Very solid and just feels right in your hand, I love the packaging and the little extras like 2 types of eye cup. 2 types of dust cap.

Visually the solar views are stunning, Every filament and prominence just oozes detail and the image is bright and very crisp, A lot crisper than my old eyepieces even after a thorough clean. The field of view is large enough for the disk to be fully visible without any signs of edge drop off even while wearing glasses. So there is excellent eye relief as well.

I also like the modular build on them as with the optional T-rings and spacers you can do almost anything with the Hyperion.

I can definitely recommend the 24mm and probably the 21mm as well for full disk viewing with the Lunt, It's a brilliant combination.

So if your into solar viewing, No matter what make of scope you have, Invest in one of these Hyperion's, You wont regret it

I use an 8mm Baader Hyperion as the main eyepiece in my 12” f 4.9 Dobsonian and it is excellent. It gives crisp, edge to edge focus, and the generous field is ideal for the Dob – less nudges per minute!
I also put in a 28mm FTR to make it into a very good 5mm eyepiece for the few nights when the seeing is good enough. In this mode it seems to retain the generous 68 degree apparent field, but there is a noticeable loss of eye relief. You have to fold down the rubber eye-cup; an adjustable screw-out cup would be nice here.
It can be converted to a 22mm focal length by removing the front lens group, but then the eye relief seems to virtually disappear so I’ve never made use of this mode. (I’ve already got a perfectly good 25mm eyepiece.)
Another minor point is that although it can be mounted in a 2” eyepiece holder, my focuser will not extend far enough out to focus it like this. I would need to add a 1” extender tube, so it has always been used in the normal 1.25” holder.

Baader Hyperion eyepieces are great pieces of kit, not only for visual work but also great for imaging with the optional T mounting ring that allows you to attach a DSLR directly on to it for afocal imaging. This ensures a firm fixture that holds the camera square to the image train at all times. I use both my 5mm and 13mm Hyperions for all my white light solar imagine with my DSLR, though the 13mm is a bit too tight and I could really do with a 17mm as well!