effectively they work the same, but the Race can/has to be hooked up to a comp or palm pilot to change major settings, but can change a few settings via grip. This can be good or bad depending on the situation. for a main setup it's good coz you can change a lot of settings in one go withouth having to go through every individual menu and sub menu to change things. It can be bad if your on site and need to change settings and you don't have a laptop in your car or a palm pilot in your bag.
Another advantage of this is that you can download and install the new firmware when it gets released, whereas you would have to find an eclipse tech to be able to do that to your e frame.
Also the race has a rechargable battery which will last 10,000 shots, whereas the e frames run off 9v and weren't very battery efficient back in the e1 versions, so you have to keep an extra supply of 9v in your bag.
The eclipse frames use magnets to return the trigger, whereas the race uses springs.
One of the main advantages of the eclipse frames is that they came with eye's, reflective eye's but eye's none the less. Race have break beam eye's but you have to buy the eye's extra and either install them yourself, send your marker to belsales to do or send it out to denmark if you didn't have a proper cocker body (belsales won't do it unless you have a proper cocker body).
That combined with the fact that the eclipse frames were cheaper made them more popular with the cocker community. Both have their good points and their bad points, and each person who uses whichever frame they use prefer that frame to the other. All in all it comes down to money and the feel of the frame for you.
Because there are so many eclipse frames out there it will be easy for you to borrow one and have a go and you should be able to buy one quite cheaply now with everyone selling them to get ego's or DM/Proto 06's etc. Race owners will be more than happy to let you have a go with their marker, but there aren't that many for sale out there unless you want to get one from the states (their bigger out there than over here).
I hope this helps,
Charlie.