Last one I bought was 25I, some reviews said the I was worth the extra $10.

When putting cameras out sometimes it can be hard to get them right. To high, to low, to far one way or other. So good to check them right away, or walk around so you have some pics to look at. I havn't, but if not getting back for a long time, a laptop would not be worse, or adapter to read SD on phone. I bought one, but it fell apart.

Some trucks can view the cards now too.