Personally, I'm a team guy. I hate it when I get stuck with rambos in suicidal, regardless of their perk or skill. I've had plenty of games where my team has agreed to fortify an area and one of our guys gets bored because he's not leading the scoreboard. These characters then abandon their posts to steal kills from the rest of the group, or just stand at their post and try to cover the rest of the team from that post, neglecting the halway or room they're supposed to be covering. The team gets ambushed from that post because the person who agreed to cover that post didn't like being second on the scoreboard and in suicidal it can be hard to recover from ambushes.
Take the offices for instance, first floor the main hall and stairs in the back corner. Played several games where a rambo wants to hold the stairway, but as soon as the wave starts rambo either heads up to the roof or stops watching the stairs to join up with the guys guarding the hall entrance. Heck, I've had times where rambo actually goes behind us and opens the sealed door so he can try to take all the kills behind the door, then either dies or panics and gets the entire team wiped.
Ramboing is fun, and a lot of times it's the only way you can get the exp you need since there are so many kill stealers these days, but try to be smart about it. This means stop "rescuing" team mates who clearly don't need it (exp. the story about the guy sniping the clots for kills even though his friend clearly had his area covered), help your team mates when they do need it (stealing another example from above, crawlers attacking them from behind), and keep in mind that if you steal all the kills you're also stealing all the income. And a note, since I play medic 9/10 times, don't expect the medic to abandon the rest of the team to chase you down and heal you.