No they're not. I've been flying them for years, taken a hard battering and still going strong, not had any problems with mine whatsoever. Also ,personally, find them quite good in the buggy. You may have had a bad experience with them, but I know that there are many people happy with them.
Perfect for people on a budget.
Have flown the Pepper, and I like it, nice stedy power through the window. And for £110 you can't really go wrong. Would consider the Bullet though. Like said before, depends on how much cash you got to spend.