1GB or 2GB?

You can always try it now , it's a good time with the introducing price !

No one can answer that but you. Only you know your usage.You are correct that with the roll-overs, bonuses and perks, you will have more data than with other providers. It never hurts to have a buffer of data. I think better to have a little more and possibly gift it and get in return as needed than running out. Like you said, in the end it's only $2 more a month now. If you want it later, after intro prices, it will likely be more..

As you said "I sometimes" , if it it does not happen often then 1G + Roll over should be good for you.

it's always nice to have some extra data, especially with only the $2 difference. And with roll-over, if you're not using all your 2gb when it accumulates it makes it even more worth it.

Don’t forget that bonuses apply only on ten next billing cycle and the roll over last 2 cycles. If you think that you need more than your plan and bonuses twice a year and buy an add on 500 MB for 8$ it is wort it to take 2GB.

I took the 4 GB and while running zero Wi Fi I barely hit 1 G last month.
Keep in mind that I am an adult, not a 24/7 tweeting , downloading teenager.
With the rollover, I will be giving away on average 60-70 % of my data monthly.
I gave away 4 x 500M just last night on Reddit.
I expect that I will use more data over time, and have no issue with the 4 GB price.
Obviously data use and needs is a very personal thing.