Do yourself a favor and stay away from the pennies. Your pocketbook will thank you. Find yourself a broker who you can work with who will help you find solid growth stocks, either listed or on NASDAQ. GLTU.
Etrade does have some restrictions on certain penny stocks but not that many. One thing you need to take into consideration. If you are daytrading the pennies it isn't a problem and you probably aren't holding any. If you have a portfolio full of penny stocks, you may have a problem transferring them to another broker. That was a problem years ago and I would guess it still is. I would suggest that you call up whatever broker you are interested in transferring to and pick their brains with questions. Ask them if you can easily transfer penny stock and if they charge and additional fee for it.
I can tell you this. I started in 1996 with Etrade. They were terrible years ago but so were everyone else - it was all new. I used four other brokers over the years - kept my small Etrade account while I tried with others. I now am using Etrade exclusively for the past five years. I have to say I found problems with all the other brokers I used except Ameritrade - they weren't bad but Etrade tools were better. Etrade has evolved to become a pretty decent broker now.