I'd estimate about 1Mbps-2Mbps depending on time of day, traffic, etc.
The thing about SmartBrowsing is you can't really test the speed of it since sustained downloads aren't affected by the SmartBrowsing feature, so running a test generally "halts" SmartBrowsing and the results won't look as good as normal browsing feels.
It allows you to browse normally as long as not going to pages with automatic videos playing. Trying to download files will cause full throttling of around 150 kbps to kick in. Recommend you install ad blockers on all browsers.
I was able to find your sales call and review it. Your initial post is basically a quote word for word on what the sales agent said. We'll be escalating this to their supervisor and the corporate manager for this particular sales center for additional review.
With that said, I'd like to offer the opportunity to cancel your services without an early termination fee. Please let me know if this is something you'd like to do .