The reason people keep recommending the 465 is it's about the last scope Tek made that a DIYer can repair. And because it's a Tek, it doesn't often need repair.
The 2200 series and later all use custom ICs that haven't been in production for years, sometimes decades. Repair means finding another broken unit with a different problem so you can scavenge it for parts. The thing is, though, all models in a series will tend to fail in similar ways, so often finding the parts scope is difficult. Broken scopes usually won't be diagnosed at point of sale, so you just have to buy them and hope for the best.
We have a TDS-320 at work, your new 420's little brother, and it is a very solid little machine, still quite useful today, 15 years past when we bought it. It's a DSO, so you can use it for more things than a CRO like the old 465.
In fact, the current low end of Tek's line are basically just miniaturized versions of these 90's scopes. There's nothing exactly like the TDS 420 in Tek's current line. If there were, it might be called a TDS1014B. The modern ones are better in some ways, of course -- more samples, more memory, modern I/O, sharp LCD display, color available, smaller -- but the main thing the new scopes have is that they just cost less than the old ones did when new.
