They're reasonably good for the most part. Have a few quirks like any other machine ... and numerous detractors on this board, like any other machine, LOL.
The washer design is clever and mechanically simple, but somewhat electronically complex. The topload dryer is clever, but mechanically elaborate compared to traditional designs.
I have four washers: one GWL08 (1999) agitator toploader, two IWL12 (2004/2005) agitator toploaders, one 2009/2010 AquaSmart HE/impeller model ... all in good working order. One 2010-ish agitator toploader that's a mess.
I have three of the topload dryers: two in fine working order, the other (with the 2010-ish washer) needs attention.
There are two discussions with pictures on disassembling the dryer in this section of the board, one earlier this year and one several years ago.
Which specific models do you have?
Beware that the pump in-common to many of the agitator models is no longer available, other than stock that may be on-hand (if any can be found) and used specimens via eBay.
I'll be out on a family trip for a few days so won't respond further until later into the weekend.