If you or the OP dont want to do the leg work to optimize your systems no problem Its your system and your call. You could just send it back then. Just bear in mind that as long as the components are within spec hes not going to get anywhere with whomever he bought it from.
Also as i pointed out earlier the OP is comparing apples and oranges in my opinion. You cannot be comparing the sims performance in March with a screenshot taken a couple updates before and try to then chase and expect that level of performance. I still affirm that under the present build on approach to a med/large airport depending on a bunch of factors 33fps is expected. Yet OP is pointing out screenshots taken before the UK update as the goalposts when here we are in June 4 major updates later
And again there are more appropriate comparison benchmarking applications that i trust than userbenchmark. A benchmark program needs to be standardized and objective and with them that comes into question.
But carry on.