Every i7 system has great performance including this one. I had seen some old Dells 3010 to 3040SFF with problems in motherboards and specially micro factors because of too old age of capacitors and other components. But from 6th generation or higher from Intel there are no problems. On Dells SFF or desktop computers, you cannot overclock processors with "K" ratings which they are open and not locked and some motherboards can alow it.
On Dells you cannot so make sure you buying fastest processor possible and avoid I3 or just pentium with 2 cores. Even those are still OK for web browsing and computer basics.