For those unfamiliar with the character, Henry Higgins is the linguist who transforms the London flower girl into a lady in George Bernard Shaw's play Pgymalion; the musical My Fair Lady was somewhat based on this play, but as I have never seen that musical in its entirety, I can't give assurance that the comments I make will also apply to its version of Higgins. Connor Temple is, of course, the tech nerd of Primeval.
In my comparison of these two characters, I must first admit the obvious differences. Henry Higgins is middle-aged, while Connor is in his twenties. Higgins is interested in language, while Connor's focus is technology and evolutionary biology. Higgins is, well, rude and pushy, but Connor isn't.
The main similarity I drew from, though, is both characters' eccentricity. Or you could call it ridiculousness. Being the character of a play, Higgins is going to vary depending on who's playing him; the actor I saw gave him the most hilarious stage presence and energy. He's always thinking, always speaking, always working on some sort of project. He's the odd genius, much like Connor is. Connor is also busy, moving from the anomaly detector to the locking mechanism to the dating calculator to New Dawn, all while going out to help the rest of the team in the field. He has odd mannerisms like Higgins does: he's been known to skateboard across the ARC and makes his frequent nerdy jokes.
They're both characters you easily love as characters, but may hesitate about meeting in person. Henry Higgins, as I said, is pushy (just ask poor Eliza)--he knows all and his way is best. And while Connor is an overall nice person, he does have annoying habits (just ask Lester, who threatened him if he ever put his socks in the bread-maker again--to which Connor innocently responds, "I was keeping 'em warm"). Given the two, though, I think Connor would be easier to live around. You'd just have to roll your eyes sometimes (like Abby does), but you wouldn't be driven to pick up and leave (like Eliza does--in some versions of the play, that is, and what I believe is the intended version).