I tested out the Blumil Segway conversion yesterday, so here are my first impressions for any that are interested.
The Blumil (http://www.blumil.com) is one of the cheaper Segway seat kits you can buy. Even so, it retails at $3,650 (£2,500), so it's only cheap in a relative sense.
What you get for your money is a seat and supporting frame, stability legs (and a mechanical handle to control them), and a removable T-shape steering column. You need to buy a Segway to attach the Blumil to, which adds another $7k or so to the bill. Obviously, buying a used Segway can help reduce the outlay.
The Blumil is pretty unspectacular in appearance, but that's not a bad thing. Some other seat kits (like the Ginny, Sui Generia, Going, etc.) are much flashier - and much more expensive - but the Blumil just says "I'm well-made and get the job done."
Riding the Blumil-equipped Segway was very easy. I was concerned I'd need a lot of upper body strength to stay upright and control it, but nothing could be further from the truth. The seat was supportive and kept me upright and in position, height was good for my 6'1" body, and my legs fell naturally on the footplate.
Getting on and off the Blumil/Segway was straightforward. The kit includes stability legs that immobilize the Segway, enabling easy transfers. Deploying these is a simple matter of pulling a handle on the left side of the seat. The handle does require a bit of arm strength, however, so it was a bit of a struggle for me. I would need a longer lever or for the lever to be repositioned if I were to buy this product.
Once on the Blumil, you turn the Segway on via the control key (a little disk-shaped fob that comes with the Segway), push the stability-leg handle forward, and your Segwaying! It only takes relatively small torso movements to make the device go (lean forward) or stop/reverse (lean backward). Steering is accomplished by pushing the steering column left or right (the lean-to-steer feature of standard Segways is disabled by the conversion). From a stationary position, a push left or right on the column turns the Segway around on the spot.
Other than having a seat on it, the chair behaves like any other Segway. It goes 12mph, gets about 20 miles range and is huge fun to drive.
The Blumil works with the Segway i2 (including the i2 SE) and the X2 (including the X2 SE) models. The i2 is the "around town" Segway, with a 25.5" width. The X2 is the "all terrain" version with fat tyres and a 33" width. The Segway forums say if you want the best of both worlds, get an X2, then buy i2 tyres and mudguards. You can then swap the boots back and forth, depending on your plans for the day. Trying to convert an i2 to an X2, however, causes hiccups with the programming (the Segway thinks your on a street when you're actually halfway up a hill and goes into panic mode, because streets aren't supposed to be like this).
In any case, I strongly recommend the seated Segway as a mobility solution. Whether the Blumil is the specific solution for you is a matter of personal taste, but I found its no-nonsense approach very appealing. The cost is another major consideration, since $12k is nothing to sneeze at, especially when the chances of getting insurance to pay for it are effectively nil.