no no, they are decent kit for what they do, its just a case of they havn't been made for many many years now and all electronics arn't the most reliable as they get older.
Link vs syvecs isnt as big a gap as you think, its a toss up i've been making for mine. What you don't find out till the time you have one fitted is you need certain extra things, for example to use the full features and get the best out of it you need a sensor pack is about £1000 for decent sensors and installation.
So for mine,
Link ecu £1400 (ish), was quoted around £3k fitted inc fuel flex etc
Syvecs S7L ecu £2100 (ish), was quoted around £3.5k fitted with fuel flex etc
So about £500 new (seemed to be less cost for the syvecs installation and mapping so could just be a bit company dependant as clinic is syvecs home base of course)
Fitting, mapping and sensor pack, fuel flex, cal switch etc is all gonna be the same across them. which all adds money on to the cost but would be the same for both.
The syvecs does have some additional features that the link doesn't, rolling launch controll, more inputs and oututs allowing more things to be connected.
You can pick up second hand syvecs now and again so an S6 would do the job and prob be around £1500.
But that said the link is more than enough for most setups.