I thought I would share this experience incase any other members find themselves in a similar situation.After many years of receiving Netflix DVDs in the mailbox, about a month ago I decided that it was time to update to streaming. My main concern was that I had been perfectly satisfied with my TW "everyday low price" internet connection at $15 per month and a consistent reading of about 2.35 mb/s. The next plan up is 6 mb/s for $50 per month. Everything I had read and been told indicated that I would need to increase the speed and price to successfully stream TV. I finally decided that I would incur the extra cost if needed, but first I was going to take all possible measures to try Netflix with my current bit rate.
I purchased the Roku 4 as it seemed to be the newest technology and highest rated streaming box. I also drilled through an interior wall so I could connect the Roku directly to the modem/router with a 25 foot ethernet cable. When switching from Netflix DVDs to streaming, I chose the 1 screen at a time SD plan as I certainly did not expect full HD and live alone as far as multiple screens are considered.
I have been very pleased with the results. Most selections start out with about 10 to 20 seconds of buffering, but never stop to buffer after that. The resolution as shown by pressing the * button on the Roku starts at a blocky 380 lines but within a minute settles at 480. I would rate the overall picture quality on my 40 inch screen as just very slightly rougher than DVDs, which are 480 of course. The few other "free" channels I have checked on the Roku do not stream as well.
I hope this information proves useful to someone else in the future.