I do. But it would have been a very different character arc.
For one, who knows when Spike feel in love with Buffy? Maybe while hanging around her, not fighting her in season 4 or early season 5. He felt something for her before that, according to a flashback, but it might just have been fascination.
So he might have needed a reason to hang around her, unless stalking would do. Maybe tehy had to work together to stop a apocalypse?
Or, he was already in love with her before he got to know her better. which kind of makes me think he would be more prone to turning her, since he didn't know her well, wanting her good qualities to stay, which might not happen if she turned(that's assuming he liked her good qualities).
Then, let's say he confesses his love. I bet he would try to do nice things before that to impress Buffy, but without the chip his love for Buffy would probably not have been enough for him to not kill people, which would have been a problem, that I don't even think suicidal depressed season 6 Buffy would overlook. We would see a battle between his need for Buffy and murder.
Anyhow, Buffy would tell him to back off. Then I can see a "be with me in the dark"-seduction thing starting, like in season 6, maybe leading to a torture/rape/turning event happening to try to convince Buffy to be with him. Which might make him get a soul.
So I think it could have turned a lot more ugly if Spike hadn't had his chip. I don't believe that he ever became nice before he got a soul, like some fans think, I think he was bad to the bone all the time. But it could be that his time with the scoobies made him realize what humans wanted and needed and act accordingly. Made him see that being nice will get you further than pain with humans, something that wasn't true with in his relationship with Drusilla, which must have shaped his "romantic" beliefs and actions. I mean, in Lover's walk, he thought torturing was a good idea to win Drusilla back and in Crush he ties Buffy up. How big of a no no it is he might not have gotten until hanging out with the scoobies.
To sum up; it would be a very different journey and the writers might have to struggle unless they re-made his character.
But I do believe it would be harder for him to want a soul. I think I recall Spike saying in Crush that the difference between a chip and a soul wasn't big(anyone who can verify?). If he really believed that, him getting a soul wasn't a big thing for him. Which it would have been if he hadn't had a chip. Then he might no have thought "I already have a chip, might nas well get this pointless soul." or something to that effect. I do wonder if he really thought there was no difference though. Kind of scary, thinking how vampires can be so out of touch.