This is a situation in which you are experiencing positive and negative feeling based on both positive and negative experiences. If one side was all bad and the other all good then your decision would be a “no brainer”. But life is rarely like that. Along with conflict comes stress and the main source of psychological stress is “change”, even good change.

The Holmes Stress Scale which ranges from a low of zero to a high of 100
lists the stress levels for a number of work-related  factors as follows:

Change in financial status --------------38
Change to a different kind of work --- 36
Change in work responsibilities -------29
Trouble with boss ------------------------ 23
Change in work hours -------------------20

How you make your decision should be based why you were leaving in the first place, despite the conflicts and stress.

Salary and Benefits

If you were leaving for money only, then maybe you should stay. But this depends on how the negotiations had gone before. If the company had always promised an increase but never came back to you with anything concrete, it means that the next raise will not be forthcoming either and you will only be delaying the inevitable. In this context, you should evaluate the other reasons for staying to ensure that where you are is really where you will want to be in a year or two.

Working Conditions

If you are leaving to become exposed to more sophisticated technology or innovative production techniques or management systems, or a combination of all three, then you probably should still leave. If your present company has not already allocated the budget to deal with these areas, they are not likely to be able to put these in place in the short term which will only spell more frustration for you.

Chance to use Newly Acquired Skills/Qualifications

If you are currently employed as an Accounting Clerk, but you have totally revamped your qualifications and you are now a qualified Computer Network Technician, unless the company you are planning to leave has space for you in this capacity, you are going to be restless and not as productive as you should be. In this case, you should leave.

Scope for Upward Mobility

If you have met with your HR/Personnel department and they have not provided feedback on your career path within the company and there is still a fair amount of foot-dragging when you ask your manager about this, leave.

If the company is willing to discuss your interests/abilities and to place you accordingly or to provide opportunities to develop you along that path, and you were generally happy there then you should consider staying.

Poor Working Relationships with Co-workers and/or Managers

If there are longstanding issues with the people you have to work with daily, moving to a new environment will give you a fresh start, and a chance to do it right this time. Remember that if all/most of the relationships are bad that is really a reflection on you. You are the sole common denominator. More money from your old employer will not resolve these difficulties.