What would you rather have?

I wouldn't care which powers you picked, as long as you had a somewhat team build. No one truly knows your slotting, they just see a bubble, or fire, or ice, or green numbers. They're not gonna say, "Oh, he/she isn't purpled out. Kick!" But if you got a bubbler and you don't see 2 bubbles, or 1 bubble and a reasonable replacement power that takes it's place(i.e. not team tp), then something is up. I never kick because my in-game life isn't that dramatic, but I would ask you why. Then you would say, "Oh, this is my solo build." And then I would say, "Oh, just wondering." and proceed to punching people in the face again. I get more bodies to beat up and you get to have fun--win, win!

I don't like dictating how people play, but if you ask me, and I'm leading, I'd answer that with a few questions:

1) Are you hitting stuff?
2) Why aren't you hitting stuff?
3) Can you hit stuff more?

Okay, seriously, I assume you'll use whatever you've got to help the team. Defense stuff, Knockback stuff...whatever you've got I hope you're using it fairly intelligently, but what I -prefer- is a team of screaming lunatics all blasting the crap out of stuff and having fun while doing so. If your solo build is more aggressive, I'm happy with that.

Whatever build you figure you can achieve the above with is fine with me.

I agree with "The slotted vs unslotted trumps everything else".

Slotted would be in the roughly 21% defense range with dispersion and maneuvers.

Unslotted bubbles, dispersion, and maneuvers would be in the 28% defense range

I doubt that 7% was worth everything else that was lost in the unslotted build.

PS: Defenders are still defenders, even when they do use their secondary.

Sounds like a pretty lousy deal for the guy with the star.

"Would you rather have the lowest damage character in the game* or the equivalent of a SK'd level 8?"

* It is possible that there are characters that do slightly lower damage; I haven't played EVERYTHING.

I wouldn't accepted a invite TF with an unslotted build either.

If as you say the team was all over the place to the extent that you weren't within range of any of them to bubble them within 4 minutes of last bubbling them, then I think the real answer is that you need a travel power or the combat jumping/hurdle combo on your team build so you can keep up with the team.

The bubbles have a range of 80' but dispersion bubble is only 25' and leadership 60' so if as you say they didn't stay together enough or moved too fast for you to bubble them they would have been getting absolutely nothing from your solo build apart from gimped blaster damage, but your secondary, Energy blasts are split with 80' and some 40' range apart from the snipe which means (if you were fighting) you were at least in bubble range of the tank some of the time, and if the tank is doing its job and agroing well bubbling just the tank is a huge benefit to the team's survival nobody else really NEEDS a bubble. Although of course with the full team bubbled and scrappers not having to worry about AoEs, blasters free to blapp and defenders attacking instead of healing any stray agro the team will roll better.

As to your original question, it would depend on the team, and in this one which was rolling along quite nicely without the bubbles and you adding either gimped bubbler or gimped blaster to that I would have to say "What I would rather have" would be a blaster or scrapper.

Now stop wasting your time reading the forum and go respec into some movement then slot out your team build.

I would probably have said to keep running the build you were using at the time and switch over if for some reason we were having problems. Basically what you ended up doing in reverse.

As others have said, most of the game is not so difficult that a power or two will make a life or death difference to a well-run team.

Oddly enough, I have an FF/Energy at about the same level which I discovered at level 16 to be completely unslotted. Evidently I had respecced the character at some point and then shelved her for a long time. When I finally started playing her again, I started wondering in mid-mission why she felt so weak. Sure enough, she was a lot more fun to play after I'd run a few missions and got enough good drops to slot her properly.

So yeah, I'd take the slotted character over the unslotted one.

I have dual builds on my Empathy/Sonic, with a solo build that uses only Healing Aura, and the RA's from the primary. My teaming/general purpose build is a balanced build with both primary and secondary powers slotted effectively. I mention this because were I in the OP's position with this toon being the one in question, I would never consider playing on a team with the solo build, as it's just missing too many key powers to be effective for that purpose, even if the team build was unslotted.
However, this is a FF we're discussing, and as such I don't really think it a major concern if they don't have the individual bubbles. Sure, FF's are mainly invited for those powers primarily, but they can contribute in other ways too. If I had been the TL of the TF in question, I'd rather have the fully-slotted solo build rather than the unslotted team build. 15% +Defense is nice, but what else is the FF'er going to do for my team after those bubbles are applied? With an unslotted build.. that's right, absolutely nothing.

Adding the caveat that I do agree the best course of action was to probably not join the team at all, but that's a matter of opinion.