I supposed you are asking about the Arnova first generation models, not G2.

The 10b has a capacitive (2 points) screen where 10 has a resistive.

http://www.arctablet.com/blog/featured/arnova-10b-capacitive-screen-review/

The Archos 101 IT (gen 8, not G9) has a CPU way faster than the two arnovas, a capacitive screen and few goodies over the Arnova: bluetooth , hdmi output. Plus the system is Android 2.2 (not Android 2.1) and still well supported by the manufacturer, even if it's more than a year old.

For the G1, they probably have removed the 10b, as it does exist, see our review.

Regarding the G2 models, the 10bG2 is supposed to have half the memory of the 10G2 (256mb vs 512 mb) and the 10bG2 reference exists as both resistive and capacitive models, the rest of the capabilities should be very similar. Well, this is my understanding as the product specifications at Arnova site are not that clear. If this is correct, that would make the 10bG2 an even lower end than the 10G2, which still may be a decent product for basic tablet usage (video, music, a little web browsing).

Power wise the GPU models are about in the same area as the Archos 101 IT (gen8):

http://www.arctablet.com/blog/featured/arnova-10-g2-android-2-3-capacitive-rk2918-cpu-512-mb-review/

Archos is positioned on the middle priced Android Tablets ($200 to $400) with some rather high speed models (G9 at 1.5 GHz), where Arnova is more in budget tablets costing less than $200.