I like RES-can's suggestion. Just for the record, here are a few other options, some with the word 'trust':
We enjoyed the discussions/negotiations/talks and sensed an atmosphere / a relationship of trust between the two companies/groups/teams.
We felt/feel very comfortable with the level of trust reached in the discussions.
We enjoyed talking with you and felt/feel very comfortable doing business with you.
We felt very comfortable in our talks with you and sensed that you are someone / the kind of people (whom) we can work with.
In AE at least, if you say you can do business with someone, it implies that you can trust them to be honest and straightforward with you. A person you can work with is also usually someone you can trust.
'Trusting' often implies childlike or naive confidence, a lack of suspicion:
The dog looked up at her with a trusting expression in its big brown eyes.
That salesman lied to you and you believed him! You're just too trusting.
'Trustful' is probably less common. It doesn't have the negative overtone of gullibility, but it also usually describes the one who trusts, not the relationship or the one who is trusted. It's often followed by 'of':
His job will be made more difficult if the Iranian crisis makes foreigners less trustful of U.S. leadership.
We will never be as deeply trustful of our government as we were then.
'Trustworthy' is a personal characteristic. You could say you felt or sensed that your counterparts from the other company were trustworthy, but that could be understood as a backhanded compliment or faint praise, as if you might otherwise have had reason to distrust them. That is, if you praise them for being trustworthy, it can sound as if you think you are superior to them, not equal.
It's almost never necessary to say 'consider to be'; simply 'consider' alone is usually enough.
But I wouldn't use 'consider' for a feeling, more for a matter of opinion. You experience something as pleasant or comfortable, or you feel or sense that it is so; it's an emotional, subjective reaction, without stopping to think. In contrast, you consider or find something informative, valid, correct, etc.; it's a rational, objective judgment, after some thought or reflection.
Hope that helps. (-: