What are you guys using for analog conference phones?

I have a customer with a Polycom unit that we cannot get to make conference calls no matter what we do? It seems that I've had difficulties in the past with these units as well.

I'm looking for a known good replacement brand that I can provide to the customer that will run off of an SLC card on an Inter-tel Axxess system.

Thanks!

I've got eight of them running with no problem, on SLC-8 and SLC-16+ cards.

What model Polycoms do you have?

Sound Station, Sound Station EX, Sound Station 2W (wireless) and Voice Station 300.

I'm liking the Voice Station 300 in an office environment; inexpensive and good voice quality.

What issues are you having?