Now a days lots of PCR manufacturing company offering variety of feature and cost variation. So, this my open discussion to researcher that what parameter they follow, when purchasing PCR for their lab, and why.
I think now a days most of the company providing all these features including touch screen, although cost of PCR varies upon features. But considering the above mentioned, negotiation with company with company before purchase would be beneficial and demands minor things from company. Be aware before releasing the amount to company you got all the things properly.
I think one of the important thing is if the company has a good support service. As you mentioned above: the most cyclers from different companies have the same features but how is the local support of the companies...?!
I strongly agree this with Dr. Nadine view point. Good support service from the company will not suffer your ongoing research for long time. For this before finalizing the deal with company, ask to company representative for 4-5 reference. Means where they last sell the instrument in your state or your locality. Contact, those person personally and ask about the performance of machine and company service support. If they satisfy with support team and machine performance than proceed further.