Actually kelvin landed every girl he wanted and in fact when he went to the pub he was always plagued by woman who wanted him to bed them. Kelvin also bagged cast members including sammy winward and before she started seeing mathew wolfden charlie herself had a thing for kelvin mathew had to work very hard to get her.
You see the trick to kelvins looks is being susceptible to certain hormonal markers guys with squarish chiseled features like kelvins tend to be deemed by woman and certain men as ultra attractive due to the fact these features suggest an extremely high testosterone level which usually comes with strong dominant powerful guys. The reason others won't like the face is they are either not susceptible to those hormone markers or they see it as a threat to their own masculinity it comes back to the alpha male gene.
As for his acting i have seen kelvin act in other shows he is a very good actor can only be as good as the story lines he is given and that was part of the reason he left the show the story lines were crap.
The producers spent more time trying to create story lines for new in takes than they did for kelvin. They also spent more time trying to make the bartons in to the new sex gods of the show even though they had no sex appeal at all. They aldo spent more time trying to spice up the storylines for others who weren't as hot in the body department as kelvin as they felt threatened by his bulky muscles. Though mathew wolfden did bulk up nicely and was reportedly inspired by Kelvin to do so. Mathew also had reportedly admitted to a little bit of a man crush on kelvin.
A lot of the guys on emmerdale only started to bulk up after kelvin partially because they felt threatened by his physique the producers brought in the bartons to try and knock him off his perch but it didn't really work they lacked the looks not to mention muscle bulk to knock him off his perch. Now the only time i watch emmerdale is when Mathew gets his kit off he has a reasonable muscle bulk and looks but still cant beat kelvin in body or looks for me as i am susceptible to kelvin facial hormone markers and now he has inspired me to start a fitness regime and bulk up the muscles.
I should point out this is only my humble opinion as a biology student. I do however agree with you about the body its incredible and love his well defined cum gutters super sexy and point to his impressive bulge below. No doubt about it he has the body of a god and probably fucks like one too.