Has anyone had any experience with these, low(er) cost alternative to the usual suspects.

http://www.vr-space.com/product01.html

Review here (2008)

http://vresources.org/Wintracker_Review.html

I can't say that I have, however this website seems to give them a cost:
http://www.vrealities.com/wintracker.html

Yes I'd seen that price which is why it caught my interest.

As it's about half the cost of the anything similar I was wondering if anyone knew how it performed in use.

The problem with it that I can see is the update rate is very low when using more than a single tracker.
Might be ok for a pair of hands though, or even hands / body sensor.

It's the impact of multiple sensors that concerns me, for most applications I only think you need head and one hand tracked but all three would be great.

It's the reality of those reduced updates that I would like to see and find out about but in practice they may be OK.

For the price, why not look into old Ascension or Polhemus systems instead? For example, TheLostBrain is selling a complete setup for $1000 I believe...

Not particularily interested in an old Flock of Birds, it's a bit of overkill for what I want and the sensor cube is huge.

I already have three Polhemus InsideTrak devices, frequency modules and sensors along with a rather old Polhemus FastTrak. The InsideTraks would be ideal but they're all ISA bus devices and I'm not sure how they'd perform on the adapters you can buy.

Also what I have in mind would need to be repeatable (hopefully) so once I'd got past the development stage I'd need to be able to get new devices.