riding gear is a real debatable subject, different brands, different textiles, different claims of what they will do for you as a rider...so i 'll give you my take on it
for me personally the weather hot or cold doesn't really bother me too much either way, i lived in hot climates for years, 12 years in Nevada, then more years in Morocco, Kenya, Bahamas all really hot places, but one thing if you can get used is wearing enough clothes. Fully vented clothes or mesh gear is good when moving except it will dehydrate you a lot, so an under layer is really required (your thermal liner) and keeping it done up all the time if you can bear it, i know it sounds strange that wearing more goes against logic.
This is where the dehydration comes in and you can avoid to some extent as when you stop yes you will sweat but once you start moving you will cool down again and your sweat will act in you favor and create an evaporative cooling type effect, think swamp cooler wind over water, your wet skin will cool you down as the breeze goes up your sleeves, keep everything closed and this will last longer...obviously wetting your shirt down will act as the same thing, or a cooling vest is good.
no for the reason for Klim or some equivalent high dollar gear...
if you ride a lot, for me 63,000 in the last 22 months for example, you will wear a lot of brands gear out, literally and you will replace it, so do this a few times and you end up at Klim, the quality far exceeds the cheap companies and if you had bought it in the first place you would be ahead of the game (dollar wise) and it does perform better, much better, holds up better in an off, quality and price by design i guess i'm saying here - i am a good example of this, i have worn out most of my gear and have new Klim gear sitting waiting to go for the next segment of my ride
for cold weather...as long as my hand are warm i'm good - so heated grips
just remember if its not Goretex and some companies alternate version of it, then its not Goretex and it won't work the same even if they claim it will
hope all this rambling helps