Unless, of course, Mantis's new 90120 springs are now standard for Poweriser, in which case the difference isn't as big as it used to be and the exact magnitude of the quality difference is up for debate until he can get together with XarnuSonci and compare them with his S-Rexes.  Sorry to complicate your decision.

But it's a good thing that you asked before you got the Powerizer Pros.  Their axle for the footplate is set too far back, making you have to hold your toes up all the time, which is strenuous and annoying.  I think that they're out of production and have been so for a while, which would explain the lack of any springs below MB100.

7leagues will sell you a sturdy frame with very tough hooves, very nice springs, and cheezy-to-nice bindings, depending on how much you pay.  Poweriser will sell you frames that get a little jiggly after a while (but are not break-prone), mediocre non-scuffing hooves, excellent bindings, and the springs are a bit of a wild card.

As for your weight, please use kilograms, as that's what bocks are built in.  140 pounds is 63.5kg, placing you in a slightly awkward position.  70-90kg springs will be a bit stiff, but you'll probably be fine with them.  Better a to be tough to use when you're new than limiting when you're good at it.

EDIT: Ask the guys at a 7league store about shipping and stuff.  With the economy as it is, it's hard to tell exactly what it will cost to get a pair of 7leagues in the USA, so it would be a good idea to take a look before you make up your mind.

I'm pretty sure the point he's trying to get across is that with the heavy aluminum hoof part, there is a lot of weight far away from you leg.  The farther a given amount of mass is from the center of its rotation, the harder it is to swing, so the metal in the hoof part matters more than up at the knee binding.  Without all that heavy aluminum, the bocks feel lighter and easier to move.

It's nice to see another American bocker.  Welcome to the forum!
And darfgarf is right about 7league hooves.  They're very tough.

The bad part for these Bocks are that you could easily damage the springs from falls or other things, unlike the frame we have right now, which gives better protection...

I don't think it would be necessarily a bad thing.  With standard models, I'm bothered enough trying to keep the frame from getting scratched to hell.  You'd just have to change the way you protect your springs to cover the whole length.  It would be more difficult, but the end result would be just as tough.
While I was trying to research a bit more about them, I found this pair with some interesting covers.  They leave a bit exposed, but redesigning them for full coverage would be very easy.

Oh, and did anyone notice that they're 700 euros??  The springs are 150 euros each (on par with Powerskip prices), and a baseline pair is 440 euros?  If I ever try out a pair of Olympics, they will probably be under a different name from a different distributor.

The wiki team already deleted it, and rightly so.

EDIT: that came off a little harsh, I know, but really.  Screwing around with wikipedia for lulz?  Just don't do it.

They could just as easily claim you vandalized it and they were fine beforehand.  They're good about their warranties, so that kind of behavior can only put stress on a good thing.  Don't do that in the future.

Mr Frank, it can be annoying, but its not really that hard to change pounds or stones to kilograms.

Likewise, not being difficult for us does not prevent it from being annoying.

If you have Powerisers, the rubber part of the hoof is not replaceable anyway.  Flying Locust stilts, such as Pro-Jumps and Flyjumpers, have replaceable rubber.  Powerisers are tan, FL hooves are black.

And 7league hooves are worth it.

You'll probably void the warranty on the springs if you use the adapter, though.  It would be interesting to see how different brands of spring not made for the increased compression and different pressure points fare.

Oh hey, and did anyone else realize that the longer compression will also mean they're taller than other bocks?

I'd suggest Raptors too.  They will be plenty of fun and you'll get some nice height out of them without much strain.

Err... split?
As in the hoof broke in half?  Or did the rubber just wear out and come apart?  Either way the fools have put a 6-month warranty on their hooves, so you can probably take advantage of it.

I think pounds are irritating, and I'm in the USA.  Personally, I'm two steps short of posting a classic Captain Kirk facepalm when people ask for advice using stone.  IMO, they're the most awkward and useless measurement in popular use today.  Being a chemistry geek, I think kilograms are a wonderful unit to use for everything, particularly bocks because they're inherently international and built in metric.

Kilograms, please!  If you don't know your weight in kg, YOU do the math, don't make us.

Somebody sticky this or something.

The attachment works for me now.  I think the website is un-f***ed.

Upon closer examination, I've noticed that the hangtime he's getting around 1:45 in the speedjumper video is about equivalent to the hangtime at 0:15 here.  Even if he's on the strongest springs they come with, that means they do get at least decent height.  The springs also at least appear to be soft enough for a beginner to learn on, but it's hard to make judgment from one youtube-resolution video.  There may also be a few different pairs of springs in different sections.

Something I noticed for sure is that the guys had three or four inches of extra space between the bends in the kneebars and the attachment points.  If these bocks really are lighter as well, these might be the best fit for people a little too small for the standard adult models.  At 1:34, you can see that the top of the spring only comes up to the widest part of his calf.

That's very different from the last thing I saw called "speedjumper professional".  It looks more like another incarnation of the Up-Wing, and appears to retain its breakable heel area.  Definitely not this.  Makes me wonder what Speedjumper's up to.

The longer spring travel looks like a really good way to get more height without making the spring stiffer.