I did a practice team TT the other night over 21.7 miles with 3 other riders, chain gang style. A mix of bikes from full on TT carbon wheels etc etc to my ventura (sorry to keep harping on about it). We are all fairly similar riders based on our 10TT times irrespective of our bikes, and guess what we all rode fairly similar and completed the ride at the same time in 53.37 @24.3mph.
We are all amateurs obviously, and we worked as a team slowing where necessary to bring the group back together, mainly after the hills. But at no point did anyone on a cheaper less specced bike get dropped, least of all me!
I think at an amateur level the kit makes less of a difference, for gawds sake I even use £25-30 Rexton shoes, doesn't make me slower than someone wearing £200 shoes. However at a pro level I think you have to be on top level kit to compete with other top level athletes.
Everything I've just written is pretty obvious isn't it?